Thank you! This problem has crippled my business, and it was eating me up until I found this thread. However, I’m still having a problem. Once I followed these steps and restarted FCPX, my library opened up with the media and projects. Unfortunately, about the half the projects aren’t working. They open, but every piece of media on the timeline is black and says “missing”. It is not the same as the usual red unlinked media alert, and all of the media in the library is linked properly. Any ideas?