Final Cut "closed unexpectedly" when opening library

I have a big problem. Everytime I try to open one specific library in Final Cut, it closes "unexpectedly". It worked half an hour ago when working on my project at my school, but when I went home and tried to open it again, Final Cut closes. The library is placed on my external harddisc, so tried to open it on an other computer, but with the same result.

I have no idea why the library suddenly wont open. Has anyone any suggestion how to resolve the problem and repair the library?

First, be sure you are on the same version of OSX and FCPX on both computers.
Second, if you have allowed FCPX to make backups, locate the backup library and try to load that.

There is no option to repair a library so to speak, but you can try to manually delete the render files within it. I assume you are now saying that it will no longer open on the school and home computers. If so, in the finder locate the library on your external disc, select it and choose "show package contents". From there you can select and trash the render files. Restart FCPX and see if the library will now load the events and projects.

Post back the results of this still doesn't work.

Had a similar indecent with the latest 10.2 update. FCPX quitted suddenly. Restarted and all was fine. Happened with 3 libraries

Make sure that you have correct Read/Write permissions on the external hard disk and library file.
You can check this by pressing Command + I on the hard disk icon (or on the library file) and check if your username is not read only.

I've experienced your problem a few times and it this fixed it for me. Hope this helps!