During the Des Moines performance, after Gary comes down the stairs saying, "Sex criminals everywhere! Vicki? Vick?" he kicks the tin that Belinda had dropped earlier. The one he kicks is very clearly dented by his kick, but the original tin lies upstage near the door to the kitchen.
In the Miami matinee, after Freddy's quick change, he trips and falls and his headband and glasses fall off before he knocks on the door and falls through. In the next shot, his headband and glasses are back in place.
Glass in Lloyd's hand after he takes a pill and a drink of whiskey on stage.
As Lloyd leaves the stage asking what the show will be without him, Poppy is standing in the middle of the stage. The next shot is her leaning against the proscenium.
When the viewer see the show from the stage, fake walls are visible behind all the doors. When the viewer sees the show from backstage, those fake walls are missing from all the upstairs doors, although present for the downstairs doors. This is not actually a mistake; this is how an actual stage production is presented, and the top floor of the set rear needs to be seen clearly or half the action would be obscured.