It's happened again and this time I did lose work. Even every four months is too often. I was looking at a frozen/hung Start11 menu with none of the controls functioning, no keys, no mouse, nothing. So your suggestion above could not be tried. That's the end for Start11 with me.
If your mouse pointer did not respond to any movements then it sounds like your entire pc froze. This will not be a Start11 issue as it is a user mode app which would not do that even if it wanted to.
My best guess would be a video driver hang triggered by the open animation but that would be purely the responsibility of the device vendor.
