The Mummy: Switching Sides
The Mummy was a real hit back in 1999, but there was a continuity error that most of us missed. When Imhotep’s priests attack Jonathan and Rick, they decide to fight back. But in the first shot they’re seen standing side by side, only to switch positions in the next shot.
King Arthur: Everything
So they movie is based on a myth, but still, you’ve got to have your facts straight. So things like modern day shoes in the middle of the 5th century is not quite accurate. Aside from that the armor plates that the soldiers wore were waaay to heavy for what Sarmatian knights would have worn into battle.