I have a super old version of Word (2007, Windows version 8.1) but it has been working great until suddenly, I can no longer save any documents - not new documents or changes to existing documents. If I click on either option there seems to be no response
- it doesn't give an error message or get hung up. It just does nothing. The only "save as" option that seems to work is the save as pdf or xps. And Excel is not affected.
I've received 2 messages and have no idea whether either are related. The first maybe appears when auto-save would normally run. I'm not sure of that though.

The second pops up when I go to close the application. If I click yes, the dialogue box will disappear but Word will stay open. If I go to close it again, the same message pops up.

One more note: the features work if I run Word in safe mode.
Any help would be appreciated! Thanks!