Continuity mistake: When Ashley moves in with her two friends she breaks their bathroom mirror with a hairdryer. Later on in the movie, in the scene where her two friends are giving her a pep talk about luck, we see the same bathroom mirror in the background, which is now perfectly fine. Right after that, Ashley goes into the bathroom and looks at herself in the mirror, which has suddenly gone back to being broken.
Continuity mistake: In the "no buy, no sit" restaurant scene Ashley grabs some bacon off a diner's plate and starts to eat it, when she says her line and pulls her hands from her face there is bacon hanging from her mouth. The shot cuts and comes back to her and her hands are in the same position but it's obviously different pieces of bacon hanging from her mouth, and the piece of bacon in her hand has moved to the other hand.
Continuity mistake: When Dougie Poynter's bass string breaks in the dressing room at the concert it hits Danny Jones in his left eye. A few scenes later when the band are looking for Harry, they walk through a door backstage and Danny can be seen holding his hand up to the wrong eye in pain. Oops.
Continuity mistake: When Ashley is working at "rock and Bowl", Jake and McFly come in and hear their song on the radio. When they first hear it, they are sitting down and taking of their jackets etc. Dougie Poynter first has his jacket around his elbow and is taking his arm out, then he does this again from a different angle, then his arm is completely out and his jacket is on one shoulder.
Continuity mistake: When the band are looking for Harry, and Phillips comes in, Jake says "we thought it was normal to go on a half hour late." you can see Dougie running towards them in the background, Tom comes in and says he can't find Harry anywhere, then Danny and Dougie appear, but Dougie comes in from the side, not behind.