Fix This Strange Error Saving Files in MS Office for Mac by Removing the Forward Slash
MS Office on Mac has a very strange problem: if you try to save a file with a forward slash (/), it will crash. The good news, however, is that Macworld indicates that you can rename this file to fix the problem.
Any other app on Mac will save, open, or edit slash files, but Office throws the error you see above if you try to do so. Obviously, if you are working on your own file, you can just name the file something without the slash and continue on your way, but if you are trying to work on a file that was posted by someone else, you may have to go to the menu File> Save As and remove the “/” to save correctly. It’s a quirky, annoying little quirk, but at least it’s easy to fix.