jensph wrote: I can try to reinstall Fusion 5.01, but I'm not sure what my license is (it was installed by my IT department). If I follow the instructions linked to by kcheon will it wipe out my license? Is there a way to make a copy of the info I need before uninstalling 5.01?
It shouldn't remove the licence file however I'd back it up first anyway! 
It's located at: "/Library/Preferences/VMware Fusion/license-fusion-50-e3-201202"
Note that the numbers in the file name might differ on your system.
If you wantt, you can open it in a Text Editor and look copy the Serial Number from the line starting "Serial = ".