Sarah,
I just recorded a macro to insert a Normal.dotm building block in a plain text CC. Then wrote a custom macro to do the same thing:
Sub Macro1()
Application.Templates("D:\My Documents\Word\Templates\Normal.dotm"). _
BuildingBlockEntries("Sincerely yours,").Insert Where:=Selection.Range, _
RichText:=True
End Sub
Sub ScratchMacro()
' A basic Word macro coded by Greg Maxey
Dim oCC As ContentControl
Dim oTmp As Template
For Each oTmp In Templates
If UCase(oTmp.Name) = "NORMAL.DOTM" Then
Exit For
End If
Next oTmp
Set oCC = ActiveDocument.SelectContentControlsByTitle("Tests").Item(1)
oTmp.BuildingBlockEntries("Sincerely yours,").Insert Where:=oCC.Range, RichText:=True
lbl_Exit:
Exit Sub
End Sub
which I think is similar to what you are doing. The only way to get that error on that line that I see is a misnamed building block. If you want to wrap your template and file into a zip file and send it to me, you can and I will take a look. Just use the Feedback link on my website.
Best Regards,
Greg Maxey
Saru mo ki kara ochiru (literally: Monkey even tree from fall). ~ Japanese Proverb