Presently on Start11 v1.2 - but this happened in the beta too.
The crash problem has been occurring for the last three or four months. It started after one of the prior Windows updates. And, I was never sure whether the problem was Fences or Start 10\11. It was triggered both randomly and especially when a 'check for updates' request was sent through settings. In fact, any time that settings was opened, a crash was imminent. Explorer would crash and then it was a crap shoot as to whether I could "enable Fences" again. Most of the time, a re-boot was necessary to restore function.
The fix (for me) turned out to be shutting off "Use Start11 search in the Start11 start menu" option.
Note: I am also running the 'Listary' app in the background.
Fingers are corssed, but in the last two hours of running and trying to crash the Explorer, all has been well.
