Yeah so if I'm not mistaken it's because the way the workers are assigned their "job" relies on an array, and this array is modified when we move things around (both the workers array and the windmills one) and sometimes it tries to reach an index that doesn't exist anymore.. I'll try to fix this today because you might not be the only one that encounters this bug !
The heatwave was just the worst haha so well timed to the whole duration of the jam lol anyways thanks again and have a good day :)