Hey Guys,
this was the only solution that worked for me, without messing with the icon cache, libraries, etc.
So just restart and press shift continuously while doing so. You boot into Safe Mode.
Then set all the extensions of Microsoft Office in the Get Info panel.
You may need to do it a few times (I did it twice, because some of my files were still not repaired).
For Parallels users, like me, I have found it best doing it as follows:
- when you are in Safe Mode, browse for your Windows 8.1 apps in your /Users/YOUR_NAME/Applications (Parallels)/Windows 8.1 Applications folder.
- select the right one there
- when you are finished, restart
Now you should have the right icons displaying on your Microsoft Office files.
Best,
István