My system was crashing in FCP7. Didn’t used to, but then everything went bad. I went into Font Book and tried to clean out duplicate fonts, etc. Didn’t really help. I went and created new Disc Directories, and cleaned the files/folders using Disc Warrior. Didn’t really help.
However, I’m also using the Blackmagic-Design Multi-Bridge Pro2. Down loaded their latest driver – and presto everything works!!!