Very simple code not working

Hello,
I have a very simple code that is not working and I don't understand why because the exact same code is working for an excel document. (I guess it might be a problem with the References set up).
Here is the code:

Sub excelword()
     Dim modeleword As String
     modeleword = ActiveWorkbook.Path & "\tp3Modele.dotx"
     Workbooks.Add Template:=modeleword
End Sub

I get error '1004' file format invalid...

Here is my the references I have set up:
Visual basic for applications
Microsoft Excel 12.0 Object Library
Microsoft Word 12.0 Object Library
OLE Automation

Thank you very much for any help !