So, that was a grand update.
A few weeks ago Flash decided it wanted an update to 11.2 r202. Then I had about a week of constant Flash crashes.
Yesterday, Flash decided it wanted to update to 11. r300. Like a fool, I assumed that it would be OK. Now I'm getting constant Flash crashes when I go online.
So... well done. If there's one thing I enjoy it's having to tuck the crash window down at the bottom of the screen so I can carry on using my computer, because every time I close the crash window it reappears.