I think I have part of the solution that I found on another forum. I guess “general error” can encompass multiple problems.
Even though I have a separate hard drive set up for FCP, FCP insists on creating a Final Cut Pro Documents folder in documents folder on my internal hard drive. So it gets confused when there’s two FCPDocuments folders. Nothing in the system settings in FCP points to that location, still it creates a new folder every time it starts up.
I cannot make freeze frames, no markers gets exported with a qt-movie, if I export direct to compressor the markers appear.
The general error warning also appears directly after starting up FCP.