Got the following error for a Word document at work.
Obviously your mileage may vary in terms of the fix but here’s what I did so there’s a starting point.
Since this is a docx file I extracted it using 7-Zip. Went through the XML files in it but they seemed fine. Next I extracted another working docx file and replaced the “[Content_Types].xml” file of the broken one with that of the working one. Zipped it all back into a docx file, double clicked, and I got a different error now but the document opened fine. It complained about comments or something missing, but all that was expected as obviously I had replaced a master file with another one. The fact that it opened fine (more or less) confirmed that this file must be the culprit.
Next I tried removing bits and pieces from the broken “[Content_Types].xml” file but that didn’t help. Finally I compared the two side by side, starting with the stuff I hadn’t removed. I noticed that the broken file had an entry like this:
<Override PartName="/word/document.xml" ContentType="application/vnd.ms-word.document.macroEnabled.main+xml"/>
The same one in the working file was different:
<Override PartName="/word/document.xml" ContentType="application/vnd.openxmlformats-officedocument.wordprocessingml.document.main+xml"/>
So I replaced the line in the broken file with the one in the working file, zipped it all back, double clicked and voila! it opens fine now. :)
From this MIME types document it seems like “application/vnd.ms-word.document.macroEnabled.12” is a “.docm” file so at this point my guess is that the user copy pasted something from another document and that possible corrupted his destination document? I don’t know.