Ошибка 3464 access

I am working on a form on Access. It is supposed to insert data into a table, but I keep getting error 3464.

I am a little new to Visual Basic. This was previously working, but no longer. I am using SQL Server as a back-end. The connection works and it was inserting new rows. I have looked online but have not found a comprehensive explanation of this error.

Private Sub mSubmitButton_Click()

    CurrentDb.Execute "INSERT INTO dbo_Reporting_Table([Date], Vendor, Ordered_By, Picked_Up_By, Reported_By) " & _
    " VALUES('" & Me.mDate & "','" & Me.mVendor & "','" & Me.mOrdered_By & "','" & _
    Me.mPicked_Up_By & "','" & Me.mReported_By & "')"

    CurrentDb.Execute "INSERT INTO dbo_Items_Table([PO#], [Item], [Price], [Equipment], [Quantity]) " & _
    " VALUES(" & Me.mPONumber & ",'" & Me.mItemInput0 & "'," & Me.mPriceInput0 & ",'" & _
    Me.mEquipmentInput0 & "'," & Me.mQuantityInput0 & ")"


    Me.mItemInput0 = ""
    Me.mPriceInput0 = ""
    Me.mEquipmentInput0 = ""
    Me.mQuantityInput0 = ""

    Me.mDate = ""
    Me.mVendor = ""
    Me.mOrdered_By = ""
    Me.mPicked_Up_By = ""
    Me.Requery

    Exit Sub

Error_PopupMessage:
    'Response = MsgBox(Message, vbOKOnly + vbInformation, "Form Entry Hint", "help", "1000")
    Exit Sub

End Sub

Any advice on what I might be doing wrong would be greatly appreciated.

I am working on a database for my work and i’m trying to insert and update values from tables with sql inside the vb editor
This is my code:

Option Compare Database

Private Sub Übernehmen_Click()
    Dim strSQL1 As String
    Dim strSQL2 As String
    Dim strSQL3 As String
    Dim ArtikelNr As Integer
    Dim Stück As Integer
    Dim Lieferant As String
    Dim Bestellnr As Integer
    Dim EkPreis As String
    Dim Mwst As String
    Dim Einkaufsort As String
    Dim GhIndex As String
    Dim Datum As String
    Dim Uhrzeit As String
    Dim Lager As String
    Dim Beschreibung As String

    ArtikelNr = [Forms]![Einkauf]![ArtikelNr].Value
    Stück = [Forms]![Einkauf]![Stück].Value
    Lieferant = [Forms]![Einkauf]![Lieferant].Value
    Bestellnr = [Forms]![Einkauf]![Bestellnr].Value
    EkPreis = [Forms]![Einkauf]![EK-Preis].Value
    Mwst = [Forms]![Einkauf]![Mwst-Satz].Value
    Einkaufsort = [Forms]![Einkauf]![Einkaufsort].Value
    GhIndex = [Forms]![Einkauf]![GH-Index].Value
    Datum = [Forms]![Einkauf]![Datum].Value
    Uhrzeit = [Forms]![Einkauf]![Uhrzeit].Value
    Lager = [Forms]![Einkauf]![Lager].Value

    strSQL1 = "INSERT INTO Einkäufe (ArtikelNr, Stück, Lieferant, Bestellnr, EKPreis, MwstSatz, Einkaufsort, GHIndex) VALUES (" & ArtikelNr & "," & Stück & ",'" & Lieferant & "','" & Bestellnr & "','" & EkPreis & "','" & Mwst & "','" & Einkaufsort & "','" & GhIndex & "');"

    Beschreibung = DLast("EinkaufID", "Einkäufe")

    strSQL2 = "INSERT INTO Transaktionen VALUES ('" & ArtikelNr & "','" & Datum & "','" & Lager & "','" & Stück & "','EinkaufID ' + '" & Beschreibung & "' ,'Einkauf',NULL,NULL,'" & Uhrzeit & "');"
    strSQL3 = "UPDATE Lagerbestand SET Stück = Stück+" & Stück & " WHERE ArtikelNr = '" & ArtikelNr & "' AND Lager = '" & Lager & "';"

    DoCmd.RunSQL strSQL1
    DoCmd.RunSQL strSQL2
    DoCmd.RunSQL strSQL3

End Sub

After trying to press the button it first adds the two entries and stops at the third one just to throw an error saying «Runtime Error: 3464».
After I press debug it marks the line DoCmd.RunSQL strSQL3.

I would appreciate any answer I get.
Many thanks in advance.