It's easy to get caught up in the editing and let it go un-saved..... I have found myself in that situation more times than I can recount. Letting the editing go on for 30 to 60 minutes before realizing I haven't saved anything in quite some time.
I do try to be diligent about saving as I work. And at the very first sign of the system exhibiting a quirk or acting unstable, I click SAVE, and then close the project and cold boot both the computer and the interface. No need to keep pushing on with a shaky OS. Take a few minutes to reboot, get a cold drink, stretch the legs, take a short break and let the system come back up stable.