Ошибка dcom 0x800706ba

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Cause

The 0x800706BA DCOM error appears in an OPC Client application it is unable to connect to the OPC server, or loses an existing connection. An OPC client may actually “believe” it has a live connection to the OPC Server, but truly does not. This can happen under several conditions including:

• The OPC Client application launched the OPC Server successfully, but due to lack of permissions (DCOM or otherwise), the OPC Client can’t access the OPC Server for data. In this case, the OPC Server might actually be running, but not accessible to the OPC Client.
• The OPC Server was initially running, but access has since been terminated. For example, the server was shutdown.
• The OPC Client PC is trying to create a group, but the OPC Client PC’s Firewall is on.

DCOM Error 0x800706BA is only slightly different from DCOM Error 0x80040202 in that the OPC Client is typically unable to establish ANY communication with the OPC Server (even though it successfully launched it initially). In DCOM Error 0x80040202, the OPC Client is indeed able to establish Synchronous communication with the OPC Server.

Symptoms

When an OPC Client application is unable to receive callbacks from an OPC Server, users will notice at least three symptoms:

1. The OPC Client application will fail to create an OPC Group altogether.
2. The OPC Client application will not be able to show data updates. Instead, data values will remain unchanged.
3. The OPC Server will show as running on the OPC Server PC, but the OPC Client application will be unable to connect to the OPC Server.

Background

In DCOM Error 0x800706BA, the OPC Server suddenly becomes unavailable to the OPC Client (or simply disconnected from the OPC Client application). This can happen due to any of the following factors:

• OPC Server has shutdown without informing the OPC Client application. This shutdown could be due to a user that ends the OPC Server’s Windows process (using Task Manager) or a “bug” in the OPC Server software that caused it to “crash”.
• OPC Server becomes physically disconnected from the OPC Client application. For instance, someone disconnects a network cable, or a network device (such as a hub, switch, router, etc) fails.
• The OPC Client application is suddenly unable to receive callbacks from the OPC Server due to a change in its own Windows configuration. For example, someone might turn on the Windows Firewall, enables Simple File Sharing, changes the Security Limits of the DCOM Access Permissions.

OPC supports a report-by-exception (RBX) mechanism whereby the OPC Server sends data updates to the OPC Client (such as an HMI, Historian, APC, ERP, etc.) whenever the data changes (also known as “on data change”). OPC terminology refers to this mechanism as “subscription”. OPC Servers are able to achieve subscription updates through the use of asynchronous callbacks. In other words, when the OPC Server detects a change in the data, it immediately “calls” the client back with the data update. This is an asynchronous mechanism because the OPC Client does not know when the OPC Server will send the data. However, if you don’t set the security settings properly, these data updates will fail. OPC Client applications typically indicate this failure by setting the Quality value of an item to “Bad”.

Callbacks force an OPC Server to actively establish a connection with an OPC Client. In a sense, the OPC Server becomes a Client and the Client becomes a Server.

Test

One simple test to determine whether or not a callback is failing is to force the OPC Client to issue a “Synchronous Cache Read” or a “Synchronous Device Read.” If either one of these return values with “Good” quality, then the lack of data updates is likely due to the OPC Server being unable to send callbacks to the OPC Client application.

However, if you determine that the OPC Client application is indeed able to launch the OPC Server, but is unable to read values from it (even Synchronous), then it is likely that the User Account that is running the OPC Client application does not have sufficient permissions to access the OPC Server. In this case, you should inspect DCOM Access Permissions on the OPC Server PC.

Repair Procedures

For the complete step-by-step repair procedure to fix this DCOM error, download the complete whitepaper.

For automated troubleshooting, refer to OPC Expert, a software application to troubleshoot OPC connections. If OPC Expert fails to connect, it automatically informs you of the problem, diagnoses the cause, and suggests a solution. OPC Expert is free to download, does not require installation, and does not make any changes to Windows registry, so it is safe to use on your computer.

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Title

Симптомы

Когда клиентский компьютер под управлением Microsoft Windows XP делает запрос к удаленному объекту Microsoft COM +, может произойти сбой запроса. Кроме того код ошибки 0x800706BA может быть создан.

Примечание. Код ошибки 0x800706BA указывает, что сервер удаленного вызова (RPC) недоступен.

Причина

Эта проблема возникает, когда клиентский компьютер под управлением Windows XP освобождает удаленного объекта COM +. Примерно 20 секунд до 30 секунд после на клиентском компьютере удаленный объект COM +, были использованы DCOM на сервере RPC-порты будут закрыты. Если сеть отключена, сразу же после на клиентском компьютере удаленный объект COM +, RPC-порты, используемые службой DCOM на сервере остаются открытыми в течение нескольких часов. Это может привести к порту нехватки. Сбой будущих запросов удаленного объекта COM + с клиентского компьютера.

Решение

Сведения об исправлении

Существует исправление от корпорации Майкрософт. Однако данное исправление предназначено для устранения только проблемы, описанной в этой статье. Применяйте данное исправление только в тех системах, которые имеют данную проблему. Это исправление может проходить дополнительное тестирование. Таким образом если вы не подвержены серьезно этой проблеме, рекомендуется дождаться следующего пакета обновления, содержащего это исправление.

Если исправление доступно для скачивания, имеется раздел «Пакет исправлений доступен для скачивания» в верхней части этой статьи базы знаний. Если этот раздел не отображается, обратитесь в службу поддержки для получения исправления.

Примечание. Если наблюдаются другие проблемы или необходимо устранить неполадки, вам может понадобиться создать отдельный запрос на обслуживание. Стандартная оплата за поддержку будет взиматься только за дополнительные вопросы и проблемы, которые не соответствуют требованиям конкретного исправления. Полный список телефонов поддержки и обслуживания клиентов корпорации Майкрософт или создать отдельный запрос на обслуживание посетите следующий веб-узел корпорации Майкрософт:

http://support.microsoft.com/contactus/?ws=supportПримечание. В форме «Пакет исправлений доступен для скачивания» отображаются языки, для которых доступно исправление. Если нужный язык не отображается, значит исправление для данного языка отсутствует.

Предварительные условия

Необходимо иметь Windows XP для установки этого исправления.

Сведения о перезагрузке компьютера

После установки исправления компьютер необходимо перезагрузить.

Сведения о реестре

Необходимо создать разделы реестра для активизации этого исправления. Кроме того изменения в системный реестр для активизации этого исправления нет.

Сведения о файлах

Английская версия данного исправления содержит атрибуты файла (или более поздние атрибуты файлов), приведенные в следующей таблице. Дата и время для этих файлов указаны в формате общего скоординированного времени (UTC). При просмотре сведений о файле, он преобразуется в локальное время. Чтобы узнать разницу между временем по Гринвичу и местным временем, откройте вкладку Часовой пояс элемента Дата и время в панели управления.

Имя файла	Версия файла	Размер файла	Дата	Время
Ole32.dll	5.1.2600.3124	1,287,168	23-Apr-2007	14:20
Rpcss.dll	5.1.2600.3124	399,360	23-Apr-2007	14:20
Updspapi.dll	6.2.29.0	371,424	19-Jan-2006	19:29

Статус

Корпорация Майкрософт подтверждает, что это является ошибкой в продуктах Майкрософт, перечисленных в разделе «Относится к».

Дополнительные сведения

Для получения дополнительных сведений щелкните следующий номер статьи базы знаний Майкрософт:

Описание 824684 Стандартные термины, используемые при описании обновлений программных продуктов Майкрософт

Error code 0x800706ba is a popular error code in windows 10, but can also be found in older versions of windows like Windows XP. The Error can appear in different situations and these include:

1. When updating windows 10.
2. RPC server is not available.
3. When a request is made to COM+.
4. RPC server isn’t available in windows 10 backup.
5. When system can’t print to any device.

Whenever these situations arise, you’ll receive the Error code 0x800706ba, in this article we’ll address all these five situations and how to remove the error code so that you can continue working with your PC effectively.

Troubleshoot and Fix Error 0x800706ba

What’s Error Code 0x800706ba?

Generally, this error code is shown when the request sent to remote COM+ object failed, and this occurs when RPC server (Remote Procedure Call Server) isn’t available, or there are damaged registry entries.

Symptoms:

1. The Error code 0x800706ba will be displayed on a dialog box.
2. RPC server unavailable message will be shown.
3. Computer will be running slow.
4. Important programs on your Pc will not run successfully.
5. Blue screen appears on your monitor

Causes:

1. Corrupt or damaged system files.
2. Unavailability of RPC server.
3. Corrupt registry entries.
4. Installing corrupt or damaged drivers.
5. Installing corrupt applications on computer.
6. Presence of malicious files in your computer.
7. Virus and spyware in your operating system.

These are the common causes of Error code 0x800706ba. We will take a look at the different cases when this message is shown and how to fix it.

Case 1: How To Troubleshoot RPC Server Unavailable – Error Code 0x800706ba

The cause

1. RPC server unavailable arise when RPC ports between servers are blocked, these are the ports that are involved in the server or communication process. RPC is the X11 protocol and is within the port range of 6001-6032. In the case of RPC error code 0x800706ba, 6007 is blocked and that’s why there is a problem.
2. RPC service has stopped from the remote server.
3. Endpoint mapper that’s on port 135 can’t be accessed by remote server.

First fix of RPC server unavailable

1. First you need to test the RPC connectivity of the server you’re working on by using another server/computer.
2. This can be done by using this command; Get-WmiObject Win32_ComputerSystem –ComputerName OTHERSERVER
3. If there is a problem, you’ll see the output message in red, showing that there is a problem and if the test is positive the message appears in white showing details of the test result.
4. You can also run a test on a specific port, and in this Error Code 0x800706ba, port 6007 is affected. If everything is OK, a blank screen will show, and if telnet failed, it means the port is closed and a message that reads something like; ‘could not open connection to the host on port 6007 | connect failed’
5. If the results are negative, you need check windows firewall to ensure that RPC isn’t blocked, not only firewall, check also your antivirus software. Firewall and antivirus software are the common cause of RPC ports. So check your settings and give permissions to RPC, the problem will be solved. To make things easier, you should disable windows firewall to see if the RPC ports are now working without the error display. This is a quick way to find whether it’s from firewall settings or not.  If things are ok, it means you need to adjust firewall settings to accept RPC ports. You should also disable any firewall service that’s on the server so that you know if it’s firewall problem.

Here is how to configure windows firewall to accept incoming-remote management connections;

• Open msc (Group Policy Object Editor), this should be used to change group policy object that’s used to manage firewall settings.
• Go to Computer Configuration > Administration Templates > Network > Network Connections > Windows Firewall.
• Next is to open the profile you want to configure, either profile or default domain profile.
• You should enable these two options; ‘Allow exception for remote administration’, and ‘allow exception for file and printer sharing’.

Second Fix: Change DCOM Access Group

The Error Code 0x800706ba can arise if the computer is a member of DCOM access group or wrong authorization is given. Here is how to deal with this problem;

1. Check controller domain where the certification service is granted.
2. Check to make sure these group of domains are available; Certificate Service DCOM Access or CERTSVC_DCOM_ACCESS. Under any of these two groups that are available, you should add this domain groups; Domain controllers, domain users and domain computers.
3. Update DCOM-security-settings on the server with CA role using these command;

certutil -setreg SetupStatus -SETUP_DCOM_SECURITY_UPDATED_FLAG

net stop certsvc & net start certsvc

1. Check the COM security permissions on the server that has the CA, remote access & remote activation permissions should now be allowed to the group you’ve created.
2. Restart your computer to see if the certificate has been issued.

Case Two: Troubleshoot Can’t Update Windows 10 Due To Error 0x800706ba

This troubleshoot applies if you’re receiving error code 0x800706ba when updating windows 10.

What’s the cause?

Error code 0x800706ba in windows 10 update is mainly caused by corrupt system files that are needed to complete the updates.

First fix: Run SFC Scan

Since error 0x800706ba in windows update is caused by corrupt system files, running SFC will help fix the situation. Follow these steps to run SFC scan;

1. Press Windows Key + Q.
2. Type cmd and command prompt will show up.
3. Right on it and select ‘Run as Administrator’.
4. Type sfc/scannow in the command prompt and press enter, this will scan your pc to find any error that’s interfering with windows update and fix it automatically, you need to wait until scan is 100% complete.

If SFC scan can’t fix the corrupt files, you should use Deployment Image Servicing and Management Tool. here is how to run DISM tool on Windows 10;

1. Open command prompt, you should do that as Admin.
2. Add this command line in command prompt;exe /Online /Cleanup-image /Restorehealth
3. If DISM can’t get the files online, you can insert your installation media to fix the corrupt files.
4. In such case you need to add the following command line in command prompt; exe /Online /Cleanup-Image /RestoreHealth /Source: C:/RepairSourceWindows /LimitAccess. Don’t forget also to replace your own repair path in the command.

Second fix: Windows update troubleshoot

Windows 10 comes with built-in feature that can fix Error code 0x800706ba associated with update problems. Here is how to do that with windows update troubleshoot;

1. From the start menu, type settings and press enter.
2. Click on ‘update and security’ and you’ll notice ‘Troubleshoot’ feature listed.
3. Search for windows update and then click ‘Run the troubleshooter’
4. You’ll be prompted with on-screen instructions, follow them to finish the process.
5. And finally restart your computer when it’s done.

This fix is very effective, your problem will be solved after restarting your PC, if not let’s move on to the next fix.

Fix 3: Enabling Critical Windows Update Services

Critical windows update services play a vital role in ensuring that update packs are installed properly and if disabled will cause update problems. These important services include; Background intelligent Transfer Service, Workstation, Windows update and more.

Here is how to fix critical Windows Update Services;

1. Open Run dialog by pressing Windows Key + R.
2. Type msc and click OK.
3. A window will open that lists some services, locate workstation, windows update and background intelligent transfer services, double-click on each of these three services. Check to make sure they’re all running and are set ‘Automatic’
4. Click on apply for each and restart your computer.

Fix 4: Manual update

If you’re still receiving Error code 0x800706ba you can download the update pack separately from Microsoft since they do offer this update on their site.

Here is how you can do that;

1. Visit Microsoft update packs page: https://www.catalog.update.microsoft.com/Home.aspx
2. Locate the particular update you want to install.
3. Download button is beside each pack, click to download.
4. After download, run the setup file on your computer and follow the instructions.
5. Restart your PC for the changes to take effect.

Fix 5: Resetting windows updates components

This is also another possible fix to Error code 0x800706ba. Follow these steps to reset windows updates components;

1. Open command prompt as admin by pressing Windows Key + X.
2. When open, you should then list the commands below;

• net stop wuauserv
• net stop cryptSvc
• net stop bits
• net stop msiserver
• Ren C:WindowsSoftwareDistribution SoftwareDistribution.old
• Ren C:WindowsSystem32catroot2 Catroot2.old
• net start wuauserv
• net start cryptSvc
• net start bits
• net start msiserver

These five fixes will help you solve Error code 0x800706ba related to windows 10 update.

Let’s move to third case of 0x800706ba error code.

Case 3: Error Generated When A Client Computer Makes A Request To A Remote COM+ Object

This error is received when the client computer is running on Windows XP and makes the request to COM+ object, the request will fail and additional message will be displayed that reads; Error Code 0x800706ba May Be Generated When A Client Computer Makes A Request To A Remote COM+ Object

What’s the cause?

It’s caused by RPC ports used by DCOM on the server when they’re closed.

How To Fix The Problem

The most effective way to solve the problem is a Hotfix. Here is how to do that;

1. Download Hotfix from Microsoft that’s designed to solve Error Code 0x800706ba. The hotfix can be accessed from This Page.
2. Choose the appropriate language and install, not all languages however are supported.
3. Once you download and install the Hotfix, you should restart your computer.
4. That’s the simple fix for Error Code 0x800706ba when received from request to a remote COM+ Object.

Let’s move on to case 4

Case 4: Cannot Print To Any Device, Error Code 0X800706BA

This error code shows up when one or more printers are connected but when you try to print you receive the error ‘Cannot Print to any device, error code 0X800706BA’

This scenario also has two simple fixes.

First fix

Download a Microsoft update designed to fix the error, the code for the update is ‘KB4524147’ and you can find the update on This Page.

Install the update and restart your computer.

Second fix

1. Power up your printer, unplug the USB from the computer if wired.
2. Go to Settings, app, apps and features, uninstall all printer software.
3. Open device manager, click on view tab, select show hidden devices. You may find ‘open printer’ under driver tab, you should uninstall the driver.
4. Select the full software package if asked, do this for all printers listed that are used regularly.
5. Open control panel by searching ‘Control Panel” from windows search. Click ‘devices and printers, right click printer or any scanner that has the same name, also make sure to delete any old printer drivers for any unused printer that can cause problems.
6. Restart your PC.
7. So now you need reinstall your printer package either from a disc or download source.
8. Extract your printer software package and right to Run as the administrator. Follow the set up instructions and complete the installation.

After that, the problem will be solved. If after trying these two fixes and the problem of ‘Cannot Print to any device, error code 0X800706BA’ isn’t gone, you need to restore your PC to an earlier date.

Now we’ll move on to the final case of error 0x800706BA.

Case 5: The RPC Server Is Unavailable Windows 10 Backup Error 0x800706BA

This backup error is more popular in windows 10 but can as well show up in windows 7 and 8. The message received is ‘The backup failed; The RPC server is unavailable’

Causes

There are many causes of Windows 10 Backup Error 0x800706BA, but the major ones are;

1. Corrupt registry files that are needed by RPC service.
2. Network connectivity problems.
3. Disabled file and printer sharing.
4. Malfunctioning of RPC related services.

Solution 1: Check whether RPC services are running

From the error message you can see that it has been pointed that RPC server is unavailable, that’s why the first thing you want to check is RPC services.

Follow these steps to ensure RPC services are running without any problem;

1. Open run dialogue by pressing Windows Key + R.
2. Type ‘msc’ in the box and click OK.
3. In the list of services, you need to check for three services and ensure they’re ‘Running’ and ensure their startup type is set as ‘Automatic’. Here are the three services to check.

• DCOM Server Process Launcher.
• Remote Procedure Call (RPC).
• RPC Endpoint Mapper.

1. There is status for each service and the startup type, that’s what you should check for the three services above. If all are working as said and you’re still receiving the error, you then need to apply another fix.

Solution 2: Fix Registry

If registry files associated with RPC server are corrupt or changed the wrong way, you’ll receive Backup error 0x800706BA.

Here is how to edit your registry;

1. First you should log into your PC as administrator.
2. Next you open the Run dialog by pressing Window key + R.
3. Type regedit in the box and click OK.
4. The registry editor will open and you need to navigate to this path; HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\RpcSs
5. Find out whether RPC is properly set or not, we’ve outlined that in solution one, you should now double-click on ‘start registry key’ which is RpcSs to change the value data from 1 to 2.
6. After that you should navigate to this path from the registry editor; HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\services\\DcomLaunch
7. Check to see if DCOM Server Process Launcher is correct in the services Window, if it’s not correct you should also double-click start and change the value from 1 to 2.
8. You now head to this path; HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\RpcEptMapper.
9. Check for RPC Endpoint Mapper, if not correct, you need to go back to start key and change value data from 1 to 2 also.

By now the problem should be solved if registry is involved. Don’t forget to back up your registry before making any changes.

Solution 3: Windows Firewall Configuration

Firewall, whether it’s windows or from third-party software, they can block RPC traffic requests which will lead to errors and in order to solve this we need to configure windows firewall.

Here is how to do that;

1. Open control panel by typing ‘Control Panel’ in Windows 10 search box.
2. Click System and security, then Windows Firewall and now select ‘Allow an app or feature through Windows Firewall’ option.
3. A pop up window will appear and you need to locate ‘Remote Assistance’, there are two boxes that need to be checked, private and public, check them all and click OK.

Solution 4: Check network settings

The next fix if the error isn’t gone is checking network connection settings, and here is how to check and fix it;

1. Open Run dialog box and type cpl and click OK.
2. Network connections window will appear, right-click on the network you’re using and select properties.
3. Check whether ‘Internet Protocol Version 6 (TCP/IPv6) and ‘File and Printer Sharing for Microsoft Networks’ are enabled. If they’re not enabled check the boxes to enable them, and click OK.
4. Restart your PC and check if the error is gone.

Solution 5: Install or delete windows update

There are some Windows 10 versions that are known to display Windows 10 Backup Error 0x800706BA, Version 1803 is among the ones that show this error often. So you need to install to the latest update in order get rid of the error in this case.

Likewise, if you start receiving the Windows 10 Backup Error 0x800706BA after installing updates, you need to downgrade to an older version.

You can install or downgrade the updates from windows update settings, just type ‘windows update’ in your PC search box and windows update will show up, you see the option to check for updates and also view the latest updates installed, from the list of updates installed, you can remove the latest ones you believe are causing problem to your PC.

We’ve come to the end of the article and so far we’ve shared the best solutions to get rid of error 0x800706BA. You should choose the case that apply for you and follow the steps outlined, hopefully you’ll get rid of this error from your computer. Let us know in the comments whether you have solved the problem or not, or if you have more solutions to share with our readers.

Most likely, a lot of you already faced an error The RPC server is unavailable. (Exception from HRESULT: 0x800706BA). This happens when you try to connect to a remote computer or server through a specific MMC snap-in, WMI, PowerShell, WinRM, or another remote management tool.

Troubleshooting RPC server unavailable error 0x800706BA

The easiest way to test the RPC connectivity between the local and remote computer is to run a simple WMI query against a remote host.

In our case, we tried to query a remote computer through WMI from the PowerShell console.

PS C:\Windows\system32> Get-WmiObject Win32_ComputerSystem –ComputerName 192.168.0.14

Get-WmiObject : The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)

At line:1 char:1

+ Get-WmiObject Win32_ComputerSystem –ComputerName 192.168.0.14

+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

+ CategoryInfo          : InvalidOperation: (:) [Get-WmiObject], COMException

+ FullyQualifiedErrorId : GetWMICOMException,Microsoft.PowerShell.Commands.GetWmiObjectCommand

In this example, you can see that the remote computer is not accessible via RPC.

Note. If the RPC communication between your hosts is working fine, you should get the remote computer info in the command output:

Several common problems can cause the RPC server unavailable error:

• The remote computer is switched off or there are other connectivity issues when the RPC client cannot reach the server due to a general network problem;
• The RPC service is stopped/failed on the remote computer;
• The RPC Endpoint Mapper port TCP/135 is not accessible on the remote computer;
• The Dynamic RPC port range is blocked by firewalls between your computer and the remote computer.

First of all, make sure RPC Endpoint Mapper port 135 is listening on a remote computer. Use the following command:

netstat -ano | find "135"

Now you need to check the next things in order to fix the error The RPC server is unavailable 0x800706BA:

1. Check if you have entered the correct IP address or computer name; check if the remote computer is not currently in a shutdown/startup state;
2. Verify that the Remote Procedure Call (RPC) and Windows Management Instrumentation services are running on the remote computer. You can check the status of the services using the following commands: sc query Winmgmt and sc query rpcss. If these services are started, the commands should return STATE: 4 RUNNING. If the services are stopped, run them with the command:

   net start rpcss & net start Winmgmt

3. Or you can run the Service management console GUI (services.msc) and make sure that the Remote Procedure Call (RPC) and DCOM Server Process Launcher services are in the running state and configured to start automatically.
   
   

Firewalls may block access to the remote computer through RPC ports (this is a very common reason). If there are no firewalls on your network, try temporarily disabling the firewall apps (including Windows Defender Firewall with Advanced Security) on both the client and server sides and check the RPC connectivity. Additionally, for the RPC protocol to operate, you must check the availability of port TCP/135 (RPC Endpoint Mapper) on the remote computer side. The easiest way to test for open/closed ports is to use the following PowerShell command:

Test-NetConnection 192.168.1.14 -port 135

If the RPC service is enabled and access to it is not blocked, the TcpTestSucceeded line should contain True.

If port 135 (RPC Endpoint Mapper) is available, but the error “The RPC server is unavailable” is still present, you need to ensure that firewalls are not blocking communication on a dynamic RPC port range. The RPC Dynamic Ports is a TCP port ranging from 49152 to 65535, that must be open for RPC technology to work properly.

Check that the Windows Defender firewall has rules that allow inbound traffic on port 135 (RPC Endpoint Mapper) and the TCP RPC Dynamic Ports range. If there are no rules for inbound RPC traffic (they have been removed), you will need to create them manually.

In Windows 2003 and Windows XP, the range of ports that are used for RPC is 1024 — 65535. In current versions of Windows, the Dynamic RPC port range uses ports from 49152 to 65535. Windows allows you to change the available RPC port range via the registry. This is often used when you need to restrict the open port range for RPC on the firewall.

For example, to restrict RPC ports to a range of 6000-6100, create the following registry settings in the HKEY_LOCAL_MACHINE\Software\Microsoft\Rpc key:

Name	Type	Value
Ports	REG_SZ	6000-6100
PortsInternetAvailable	REG_SZ	Y
UseInternetPorts	REG_SZ	Y

You can force Windows Defender Firewall to open the specified range of TCP ports.

Restart all services and applications that use dynamic RPC port allocation.

You can use a small command-line tool PortQry from Microsoft to get a list of RPC Dynamic ports used by the RPC Mapper service. Use the following command to get the list of RPC endpoints from a remote Endpoint Mapper Database:

PortQry.exe -e 135 -n 192.168.1.201

In this case, 151 endpoints were found. Each RPC point has a dynamic TCP port number next to it that it is listening on. You can check the availability of the RPC port for the desired service using the PowerShell command:

Test-NetConnection 192.168.1.201 -port 49703

Many firewalls block RPC and SMB/NetBIOS even if you have any-any rules enabled. In this case, you must specifically create a rule/policy to explicitly allow RPC dynamic ports.

Note. Windows RPC/DCOM connections often don’t work correctly when NAT is used. Try to connect to your RPC server directly, without using NAT.

Certificate Enrollment Error – 0x800706ba The RPC server is unavailable

If you are facing an error The RPC server is unavailable 0x800706ba when performing the automatic registration of a certificate on a domain controller or in a certification authority, you can find the following error event in the Event Viewer > Application log on the server:

Source: CertificateServicesClient-CertEnroll Event ID: 13
Certificate enrollment for the Local system failed to enroll for a DomainController certificate with request ID N/A from ServerCA.contoso.com ServerCA (The RPC server is unavailable. 0x800706ba (WIN32: 1722))

Or:

Source: CertificateServicesClient-AutoEnrollment EventID: 6
Automatic certificate enrollment for the local system failed (0x800706ba) The RPC server is unavailable.

When you try to enroll the certificate you can see the following message:

An error occurred while enrolling for a certificate.
The certificate request could not be submitted to the certification authority.
The RPC server is unavailable. 0x800706ba (WIN32: 1722 RPC_S_SERVER_UNAVAILABLE)

In this case, the domain controller or other client fails to enroll for certificates from the CA.

This problem can have several solutions, but in most cases, the source of the problem is that your computer is not a member of the DCOM access group (allows access to the certificate service via DCOM) or incorrect permissions are issued. This most commonly occurs when the CA is installed on a DC.

Follow the next steps:

1. On the domain controller on which the certification service is deployed, you need to make sure there is an  Active Directory group CERTSVC_DCOM_ACCESS or Certificate Service DCOM Access.
   Note. If the CERTSVC_DCOM_ACCESS security group has been accidentally deleted, open the ADUC console and manually create it in the Users container (Group scope: Domain local, Group type: Security).
2. Add the following domain groups to the CERTSVC_DCOM_ACCESS/Certificate Service DCOM Access group: Domain Users, Domain Controllers, Domain Computers;
   
3. Update the DCOM security settings on the server with the CA role using the commands:

   certutil -setreg SetupStatus -SETUP_DCOM_SECURITY_UPDATED_FLAG
   
   net stop certsvc & net start certsvc

4. On a server where the CA is deployed, check the COM security permissions. This group must have Remote Access and Remote Activation permissions allowed;
5. After that, try to restart the computer and check the certificate enrollment.

Then check the DCOM Permissions on the server running the CA role. In some cases, even if RPC is configured correctly, incorrect DCOM permissions can block remote authentication.

1. Run the command dcomcnfg.exe;
2. Expand the section Component Services > Computers > My computer;
3. Open the properties of My computer, go to the Default Properties tab, and ensure that the option Enable Distributed COM on this computer is checked;
4. Then navigate to the COM Security tab and click on the Edit Limits button in the Access Permissions section. Check that the Certificate Service DCOM Access security group has Local Access and Remote Access permissions;
   
5. Then click the Edit Limits button in the Launch and Activation Permission section and check that the Certificate Service DCOM Access group is allowed for Local Activation and Remote Activation.

If the above solution doesn’t work, use the nltest command to find out problems with netlogon calls to a domain controller:

Nltest /Server:dc01 /query

Then check that the Active Directory CA request interface is responding:

Certutil -ping

Server “test-DC01-CA” ICertRequest2 interface is alive (62ms)

CertUtil: -ping command completed successfully.

In order to trigger the renewal of a certificate on the CA, run the following command:

certutil –pulse

If you receive the error “Server could not be reached: The RPC server is unavailable. 0x800706ba (WIN32: 1722)” from the non-domain joined computer, ensure that the “Authenticated Users” group is added to the “Certificate Service DCOM Access” group on the CA server.

RPC Server Unavailable Error when Updating Group Policy Settings

When you remotely update Group Policy settings on domain computers from the Group Policy Management Console (gpmc.msc), you may receive error codes 8007071a: The remote procedure call was canceled and 800706ba:The RPC server is unavailable.

To resolve this issue, you must enable the following rules in Windows Defender Firewall:

• Remote Scheduled Tasks Management (RPC);
• Remote Scheduled Tasks Management (RPC-EPMAP);
• Windows Management Instrumentations (ASync-In);
• Windows Management Instrumentations (DCOM-In);
• Windows Management Instrumentations (WMI-In);
• Windows Management Instrumentations (DCOM-In);
• Windows Remote Management (HTTP-In).

You can create a new GPO and enable these rules manually (Computer Configuration > Windows Settings > Security Settings > Windows Defender Firewall > Inbound Rules).

Or you can activate the following default Starter GPOs:

• Group Policy Remote Update Firewall Ports;
• Group Policy Reporting Firewall Ports.

These policies contain all the necessary Windows Defender Firewall rules to remotely update Group Policy settings.

Go to the Starter GPOs section, click on each of the items, and select New GPO from Starter GPO. Create new GPOs and assign them to Organizational Units with target computers or servers.

After a while, try a remote Group Policy update. The error should disappear.

Are you facing the stubborn 0x800706ba error? The 0x800706ba error occurs due to improper system configuration.

If you have made mistakes while configuring your machine or installed a program that meddles with system settings, you are likely to face this error.

There are special software programs to fix the 0x800706ba error. However, you must try and understand what caused the issue in the first place.

What Does 0x800706ba Mean?

By definition, the 0x800706ba error represents an application or component that has failed. The error is accompanied by details of why it happened and which component failed.

This error occurs due to a number of reasons. Thus, it is difficult to rectify and prevent the error without understanding the actual cause.

Major Reasons Behind The 0x800706ba Error

First of all, the 0x800706ba error signals that something is wrong with your machine. And that the system is not able to function properly. Common reasons behind this error are:

• You have not installed some software correctly.
• There are invalid entries in your machine’s registry.
• It could be caused by malware or a virus.
• Your system was not shut down properly. Power failure might have caused the system to shut down abruptly.
• You may have deleted an important registry entry.

Fortunately, you can repair the 0x800706ba error easily. There are various tools to help you with the process.

Method 1 – Reset Windows Updates

First things first, you should try to reset windows updates. A major reason behind the 0x800706ba error is a failing program. And a program that was once running fine will fail only with an update. Resetting updates using manual methods are simple and effective.

To reset windows updates, you should follow these steps:

• Login to your machine as a system administrator.
• Now, open the command prompt. Pressing the “Windows and X” keys will open the command prompt in admin mode.

• Next, you should type the following commands:

net stop wuauserv
net stop cryptSvc
net stop bits
net stop msiserver
Ren C:\Windows\SoftwareDistribution\SoftwareDistribution.old
Ren C:\Windows\System32\catroot2 Catroot2.old
net start wuauserv
net start cryptSvc
net start bits
net start msiserver

Once the above commands are executed, verify if the 0x800706ba error is rectified. Technically, resetting windows updates should fix the problem permanently. That is because the 0x800706ba error is caused by a change that conflicts with the existing configuration of your applications.

The only catch in this method would be whether the reset happened fully or not. Since resetting is done manually, you should watch out for missed commands.

PS: If you are facing issues like the 0x80072f8f, click to fix them now.

Method 2 – Critical Windows Update Services

There are several Windows Update services to make sure that patches and updates are downloaded into your machine and installed without any hassles. It is important to ensure that updates are securely downloaded too!

Critical windows updates services would be Background Intelligent Transfer, Workstation, and Windows Update. If any of these services are turned off, you are likely to experience the 0x800706ba error.

To fix the 0x800706ba error caused due to Windows Update services, you must follow these steps:

• Launch the run window. Now, you must type “services.msc” and select OK.

• Next, double-click on the Windows Update option;
• Now, double-click on the Workstation option;
• Next, double-click on the Background Intelligent Transfer service option;

• And then, select “Automatic” as the mode for executing these services. The “Startup Type” should be “Automatic.”
• Now, click on “Start” and then select “Apply.”
• To complete the process, you must restart your machine.

Method 3 – SFC & DISM

In many cases, the 0x800706ba error is caused due to corrupt registry entries and system files. Windows has a built-in tool to help you handle these corrupted files. And that would be the System File Checker alias SFC.

Running the SFC scanner is a very simple process:

• Login to your machine in admin mode and run the command prompt.
• Now, you should type sfc /scannow and then hit the “Enter” key.

• You should wait for the scan to be completed. This will take several minutes.

Once the scan is done, you can expect the 0x800706ba error to be gone. However, if the SFC tool cannot fix the 0x800706ba error, you can rely on Deployment Image Servicing and Management (DISM).

To execute DISM, these steps should be followed:

• Login to your machine as an administrator and run the command prompt.
• Type the following command: dism.exe /online /Cleanup-image /Restorehealth

• If your DISM module is unable to load certain files, it will throw an error. Now, you can use your installation drive (USB or DVD) to execute the above command. However, the command to be used now is: dism.exe /Online /Cleanup-Image /RestoreHealth /Source: C:/< Path to your DVD or USB> /LimitAccess

Method 4 – Update Troubleshooter to Fix 0x800706ba Error

If all of the methods mentioned above fail, you can make use of the Windows Update Troubleshooter. Once again, this is an inbuilt Windows tool. It is often used to rectify the 0x800706ba error.

However, this tool can fix the 0x800706ba error only if it is caused by updates. If the error is caused due to failing registry files, you cannot use the TroubleshooterTroubleshooter to fix the 0x800706ba issue.

Using the Windows Update Troubleshooter is extremely simple.

Here is a step overview of how the Troubleshooter can be used:

• You must navigate to “Start” and type “Settings.”
• Navigate to “Update & Security.”
• Next, select “Troubleshoot.”
• Next, look for Windows Update & select “Run the Troubleshooter.” The following screens will be comprehensive and loaded with instructions on what has to be performed. Follow these instructions and restart your machine.

Method 5 – Advanced Solution

If you are familiar with your machine, you can choose to fix the 0x800706ba error by restoring the system to an earlier point in time.

To restore your machine to a specific time, the following steps should be performed:

• Login to your machine as an admin and click on the start button.
• Now, select “System Restore” under “System Tools.”
• Now, select “Restore my computer to an earlier time.”
• Next, you should choose a restore point. You will be given a list of restore points. Choose the ideal one.
• Click “Next” in the following confirmation window.

When your system restarts, check if the 0x800706ba error is gone. If the error is still present, you may have to choose a different restore point.

Method 6 – The Manual Method to Fix 0x800706ba Error

Last but certainly not least, you can fix the 0x800706ba error using manual updates.

Fixing the error through manual updates is not an easy task. That is because you should navigate to the Microsoft website, find their update catalog, and pick the right update. This is definitely the toughest and most time-consuming way of resolving the 0x800706ba error.

To download the right update, you must scan through a huge number of updates. You must spot the right update code, which caused the 0x800706ba error in the first place.

In general, all windows updates start with “KB.” The numbers following “KB” will help you find a specific update. Only when you find the right update will you be able to download, install, and fix the 0x800706ba error.

Here is a simple overview of how to download updates manually:

• Navigate to the Microsoft website and search for the Microsoft Update Catalog for Windows.

• Enter the update code, before which the 0x800706ba error was not occurring. Now hit “Enter.”
• You will find so many updates with a similar code. Choose the update that matches your system architecture.

• Download the chosen update and install it.
• After the update has been successfully installed, you must restart the machine.

When your system restarts, check if the 0x800706ba error is gone. Most of the time, the 0x800706ba error will persist if the wrong update is downloaded and installed.

And, if the error still exists, you can be sure that the updated downloaded was not right. In such a situation, you must repeat the entire process again.

As mentioned previously, choosing to install an update to fix the 0x800706ba error manually must be your last option.

FAQs

1. Why am I encountering the 0x800706ba error? The 0x800706ba error is typically caused by issues with the Windows Update service or software installations. It indicates a failure to connect to the necessary servers or resources.

2. Can restarting the Windows Update service fix the error? Yes, restarting the Windows Update service can often resolve the 0x800706ba error. It helps refresh the service and establish a new connection to the required servers.

3. Is it safe to modify the Windows Registry? Modifying the Windows Registry can have consequences if not done correctly. It is important to proceed with caution and create a backup of the registry before making any changes. If you are unsure, it’s best to seek assistance from professionals.

4. What if none of the methods work? If none of the methods mentioned in this article work, it is recommended to contact Microsoft Support for personalized assistance. They will be able to provide further guidance based on your specific system configuration and circumstances.

5. How can I prevent the 0x800706ba error in the future? To prevent the 0x800706ba error from occurring in the future, make sure to keep your operating system and software up to date, regularly scan for malware, and maintain a stable internet connection. Additionally, avoid making unauthorized changes to system files or registry settings.

Conclusion

Fixing the 0x800706ba error becomes easy if you are aware of how your machine was functioning before each update. Thorough knowledge of the updates executed in your machine can help you rectify the 0x800706ba error in no time!

Nevertheless, if you are unaware of the updates installed, the points discussed in this post will help you!