I've posted this several times before, and I'm not sure if anyone has looked at it, but I think it's a rather nasty problem. So here I go again:
If there is any problem with the database files when opening MJ (i.e. read only, corrupt, etc.) then you get a dialog message informing you about the problem. So the normal course of action would be to hit "OK", and fix the problem from the Library Manager. Unfortunately, faster than your mouse can make it up to the menu, the dialog comes up again after you hit "OK". So basically, you're locked out of making any changes! Your only way out is to ctrl-alt-del and quit. When you restart, you'll be in the same trouble.
Hope you guys can fix this in a future update.
Thanks
-Ted