When trying to either confirm all tracked changes via Review > Track Changes and TQA > Accept all changes in Document
or rejecting all Changes via Review > Track Changes and TQA > Reject all changes in Document
the following error is thrown:

Object reference not set to an instance of an object.

Solution:

1. Download the texteditor Notepad++ (http://notepad-plus-plus.org/)
2. Open one of the affected files in Notepad++
3. Open Find and Replace with [Strg] + [H]
4. Activate the search mode Regular expression (lower left corner)
5. In Find what: enter:

   <mrk mtype="x-sdl-(deleted|added)" sdl:revid="\w+-\w+-\w+-\w+-\w+"\s?/>

6. Keep Replace with: empty
7. Click on Replace All
8. Save your changes and use this document for translation instead