Continuity mistake: The hairstyle and length of Chris' hair is changing constantly throughout the movie.
Continuity mistake: After Chris and Kate smash the wall and enter the underground tunnel to the castle, they knock over a standing candle. In the next shot, as the monks look into the tunnel, this candle is suddenly standing again. (01:16:25)
Continuity mistake: Near the beginning of the film, Kate finds a bas relief that has been partially destroyed and replaced with unadorned stone. As it turns out, she destroyed it herself in the past. However, when she does so, she eradicates almost the entire framed portion. In the present day, only the lower part had been dismantled. (00:14:05 - 01:16:35)DavidK93
Continuity mistake: In the scene where Marek first shows Chris the sarcophagus, Marek's arms change position from shot to shot.
Continuity mistake: In the scene just before the group is sent back to 1357, as they are standing in position inside the time machine, Doniger calls up to Stern, who is waiting at the top of the stairs, "Josh, come down!" However, exactly before this, Josh Stern can already be seen descending the stairs to join the others, although when Doniger calls up to him, he appears at the top of the stairs again.