re:Error Message in FCP5Studio2 'unreadable project file or too new for FCP'

About 30 minutes ago I finished up an HD project in FCP5 Studio 2. Used compressor and output a file. Exited out compressor, batch processor and fcp. Well that file did not work very well. Re-launched FCP and holy moly! Error message stated 'This project is unreadable or may be too new for this version of FCP'. Not true, just finished up several projects this weekend. Thought it was just this project file, but tried opening all my other projects and none of them would launch and received the same error message. Any thoughts, suggestions??

Running FCP5 Studio 2, PowerPC non-intel. 9.5 gig ram. Leopard 10.5.8.


Desperate
Wayne P.
NC.