It happened to one of my sims when I played yesterday. A skill bar got stuck above it's head. Moving to another lot didn't remove it. Had to play another household and come back and it was gone. This is hard to reproduce but seems to still be present in the current version (4th december). I have no idea what is causing it to stay stuck but I have a suspicions it's related to the multi-tasking somehow.
Just to be clear, this is not about the skill bar. That has a thread here: http://answers.ea.com/t5/The-Sims-4-Bug-Reports/Sim-s-Skill-Point-Bar-Stuck/td-p/3546249/
This is about actual NPCs getting stuck at the chess board
