Apple

Suddenly I cannot use the Script Editor. I was working on a script - nothing special, just a script that would combine 3 other (functioning) scripts. I had 4 script windows open. Suddenly the size of the font of the front most script increased substantially, and the Editor froze (with spinning colored beach ball). This had happened a couple of times before, but in each instance, I'd use a force quit. When I would relaunch, the same scripts would open along with the Script Editor, all was fine and I could continue working. This last time (yesterday) that didn't work. Every time I open the Script Editor since, the 4 scripts open with it, but it is still hung up with the spinning beach ball. I tried shutting down the computer and rebooting, but it doesn't help. What can I do to end this insanity and get back to scripting? What is the cause and how can I prevent it?

Thanks in advance for help. RWY