Using the technique in this answer I was successfully embedding the contents of an RTF file into an existing Word DOCX file, using OpenXML 2.5. Or so I thought.
We've now discovered that while the created file works fine in MS Word and Word Online, the document displays without the RTF content on other viewers such as:
- Google Docs preview functionality
- Windows Phone 8.1 (which has Office functionality built in)
- Various iOS and Android viewers
In all cases, the document displays completely correctly except that the RTF content is just missing.
I did think it might be an issue in the viewers rather than the DOCX file, but for several tools to have the same issue makes me suspect it is a bug in our code.
It's a bit of an obscure case so trying to figure out the problem is proving difficult.