I've seen the same problems when using a MacBook. The editor just seems buggy there, unfortunately. Running it on PC is far more stable. If you are able to use a PC for this, I highly recommend it. It might be worth setting up Boot Camp or a VM or something on your MacBook if that's an option for you. Otherwise, you'll probably just have to avoid the actions that cause problems. I've noticed regular crashes when editing pop-up text, when pasting triggers, and editing certain drop-downs. You can manually edit the text files generated by the editor to do things like insert strings.