We had a similar situation. Although we never saw the second error message, the Word documents always opened fine. So your situation may be different.
There is a resolution in a patch release of AgileApps.
This error does not occur if you use older versions of Microsoft Word to edit the templates. We had upgraded to “version” 365 of Word, and that is when the problem started occurring.
Our work around was to edit the documents with Word 2016 or Word 2013.
This is from the release notes:
#AgileApps#webMethods