First solution - stop pirating apps! If you didn't download a pirated copy of Final Cut Pro in the first place, you wouldn't be in this predicament.
Try looking at this thread: https://discussions.apple.com/message/15837863#15837863
What cracks me up is someone having problems because they pirated Apple software, then having the b*lls to ask for help on an Apple-hosted forum!!!!
hahah yeah i quit torrenting i have nothing but legit apps now.
hope apple heard that!!!!
your post fixed my issue
but it did take more than deleting torrented apps, once your run a program with a MASReciept with someone elses Apple ID. that other ID is saved in all apps you got off of app store.
You have to delete all apps that contain the MASReciept (the terminal command tells you which ones) then quit appstore then reboot download all apps again.
it taught me to just buy my apps..