I’ve seen a few instances where an upgrade caused Final Cut to run kinda’ strangely. To resolve, I’ve just been doing a quick reinstall of Final Cut. To do so:
- First move the Final Cut application to the trash (it’s in the /Applications folder).
- From your home folder, go to ~/Library/Application Support and move the Final Cut folder in there into the trash.
- From Library/Preferences in your home folder, put com.apple.FinalCut.plist, com.apple.FinalCut.LSSharedFileList and com.apple.FinalCut.UserDestinations.plist in the trash.
- Finally, trash com.apple.FinalCut directory from ~/Library/Caches.
Once done, go back to the Mac App Store and reinstall Final Cut and open it. Those folders you just tossed out will get re-created. Your toolbars and other customizations are likely to be gone, so you’ll have to spend a few minutes getting your workspace back to the way you had it, but if Final Cut was acting oddly it should be back to normal.
Good luck!