Actually I think it was that something in the program that got corrupted. I backed up all my projects and uninstalled and then reinstalled. Everything works fine now. The only thing I didn’t do was upgrade to 5.0.3 and have used the version I bought – 5.0.
These programs are becoming too complicated and fragile. I also have FCP and that is starting to crash every time I use Log and Transfer and set the in and out points by scrubbing in the viewer. Never did that before. So I shall uninstall that and reinstall.