...
As I posted above, MS admitted this bug, promised to fix it in RS5, due end of October
Well, what can I say? Here I am, with the RS 5 downloaded and installed, and ... the issue still persists, it hasn't been fixed!
Just installed a fresh Windows 10 1809. Added myself and a family member. Did nothing else. Rebooted. Lo and behold Windows Shell error pops up.
Today I have switched my PC (1803) on 3 times throughout today. I got the error once. Logic and Microsoft do not live in the same world.