Style Sheet for Microsoft Dynamics NAV

I am working with the style sheet program to create MS Word based reports. I get the following message:

The call to member Add failed. Microsoft Word returned the following message:

The Add method or property is not available for this document is in another application

Has anyone come across this message before, and if so, what was the solution to this error?

Thanks in advance.

Have you defined any Templates in Word with proper Mail Merge fields?

Check whether the Template field is initialised with the proper location of the Word Template.