Microsoft Word: Unspecified Error Location: Part: /word/document.xml, Line 0, Column 0

Solution 1:

I had a similar issue with "comments.xml". I found a post on extracting and inserting line breaks to the xml file; "Pretty print (XML only – with line breaks)" with notepad++.

https://bhrnjica.net/2014/01/23/how-to-manually-fix-content-error-in-microsoft-word/

But it did not help me - still showed the issue is on line number 0.

I extracted the xml file from an earlier version of the docx file, then compared the two comments.xml files.

After I while, I figured out that a bookmark start without bookmark end causes this issue.

I removed the bookmark start, injected the fixed comments.xml to the docx file. After that it worked.