Further to my previous thread were the only way to stop DCS crashing was to do a reboot of PC, I've discovered that when I was using VR and created missions, after switching VR off, running DCS and being able to load those missions, switching VR back on, I'm unable to load those missions - DCS crashes just as it almost finishes loading before flight.
However, I can load and run instant action missions OK.
I've created new missions in VR (now that I've enabled it again, and these ones work OK.
The only difference might be that previously in VR I had the screen resolution set quite high, and now I'm running it at the default 1980 x 720 (or whatever the default is).