I've just noticed this in Whiterun - NPCs get rooted to the spot, and just slowly spin around in circles. I've never noticed this before in the 300+ hours I've invested in the game, and although other people have brought this bug up online (on console as well as PC) it seems very rare. The only solution I've been able to find is "start a new game".

Anyone out there happen to know a fix for this yet? Or is this still a character-destroying bug?

My mod list is BOSS'd, isn't very long by some standards, and the game is very stable (can play for hours without crashing). Ugrids is on 5. Given that this bug hits console players too, I'd guess it isn't mod-related.