During the final dance scene, when the guy doing the kick boxing moves slides across the floor on his knees he splits his pants, which are then repaired the next time he's shown.
During the final dance sequence after Monster emerges from the suitcase on the podium, the metallic cover disappears when Moose returns to dance with the people in the sand. As Andie walks up with the fire stick you can see she is standing in the sand. In the next shot she is on the metallic cover again.
When the Mob is battling the Grim Knights in the bar at the beginning of the movie, the bearded MOB dancer is kicked in the face by a Grim Knights dancer but no one seems to notice and he is immediately shown standing behind the others as though it had never happened.
In the final battle, the box that Moose carried disappears as soon as the sand starts coming down with no explanation as for where it went.
Eddy adjusts his groin at the start of the auditions in the beginning. No one seems to notice.