Looks like this is probably a problem with your simulation exploding, which has a tendency to cause the sim to crash. We've already made some steps to improve that, which will be in the next release. If you can send me a self-contained scene so that I can run to see the problem, then I can make sure that your specific problem doesn't cause a crash in the future.
If this is the problem, then the best thing for you to do right now is change your setup so that it's more stable. That's a big topic on its own. The best thing I can recommend is to experiment, start small, and only add or change one thing at a time.