FCPX Project and backups missing

Hi everyone

I have a problem with a project in FCPX (10.1.2). I work with an external HDD and I had to force-close the app last time because of a crash; now the whole project is missing. The weird thing is that the event, the media and all the compound clips I had previously created are still there and work properly!

I really need the project (it was almost finished) but I didn't find it in FCPX Library, and the backup is missing as well! The only file I have there (apart from the media) is named "CurrentVersion.fcpevent".

How can I fix this issue?

Thanks in advance