I did 2 things and seem to have solved the problem but I’m not sure which action did the trick.
The first thing I did was uninstall and then reinstall FCPX. I u google it, apple support has a step by step guide on how to do this.
The second thing I did was purchase a high performance 1TB external HD. I needed one for my video an couldn’t completely rule out the possibility that the HD I was using just wasn’t up to it.
Anyway, I spent 4hrs on the project this afternoon without any problems so hopefully I don’t encounter the same issues. Best of luck
Tim W