I don't know for certain why you are getting either message.
I recommended that you treat the document as a template because that avoids the danger of overwriting the master document/template after changes have been made.
For troubleshooting reasons, try reverting to your original plan of opening the document.
So replace this line:
Set wdDoc = wdApp.Documents.Add(strTemplatesPath & "\Master-CM-Form.doc")
to
Set wdDoc = wdApp.Documents.Open(strTemplatesPath & "\Master-CM-Form.doc")