First, thank you for trying out my mods!
In my experience, mods should not be the cause of the game quitting suddenly like that. Instead, it is usually caused either by an overstressed computer system or some kind of hiccup that OFF has with your computer setup. I also used to have this problem until I recently upgraded my computer from an Athlon X2 based system to an Intel system. For whatever reason, I am no longer getting dumped back to the briefing screen in the middle of a flight anymore.
Just in case I am wrong, first try disabling all mods and see if that eliminates the problem. If not, reduce some of your OFF graphics settings or Regional Air Activity settings a bit. You might also think about getting a better cooling solution for your CPU.
Good luck and let me know how it goes.