A colleague is working on a project in fcp7 and she gave me the project file to open on my computer.
I reconnected all the media fine (I have a duplicate of all footage on my HD).
But something wonky is happening!
Everything looks fine on her machine, the timeline looks good, clips play, etc.
On my machine, none of the clips in the timeline show up. The canvas is blank and the audio doesn't play. Red render bars are everywhere. It won't even let me render (general error).
I tried rebooting the machine, getting a fresh copy of the FCP project file, and same thing.
Long time ago, I had something similar. Try first Shane's suggestion. If it does not work, then download "Applejack" (free software). Close your machine. Restart, while holding down Command + S and then you get under the hood of the OS. Then type "applejack auto reboot" and wait 2-15 min, depending on how extensive the repairs are, that have to be done.