Revealing mistake: After Sophie faints at her bachelorette party, during the next scene it cuts back and forth between shots taking place in two rooms - Donna walking into Tanya and Rosie's room, then Sophie walking into Ali and Lisa's room, and both rooms have the very same cracks and stains on the walls revealing it was filmed in the same room, but with different furniture.
Visible crew/equipment: When Mitchie is at her locker at school, Sierra walks up to her and there is a white chalk marker line on the floor that she promptly steps on to speak to her friend.