Other mistake: Two cars with the same license plate numbers are seen as the minions are hitch hiking on the road. The plates of the hippie wagon and the old lady's car both read D-6413.
Other mistake: When all the characters (Dracula, Frank, Murray, Wayne, and Griffin) all go to one side, the weight should make the tower fall down, but it didn't. However, after Dracula leaves and Frank goes to the other side, it happens to fall on his side.
Other mistake: When Marry Anne flies into the dark forest for the first time she drops the boutonniere. After seeing the primrose petal she flies off empty handed but has the boutonniere later when she meets Roland.
Other mistake: When Riley and her parents arrive at their new home in San Francisco, several pieces of mail are sticking out of the mail slot in the door. A letter carrier would not deliver mail to a vacant house, let alone not push it all the way through the slot.
Other mistake: When Matty and Sam are having a conversation about modern games vs older games, Matty is playing a game on a Playstation 4 but the controller isn't on.
Other mistake: After Dr. Palmer and his friend Ryan have placed the miniature horses in the back of his truck, he drives off. After this, a robot runs past Ryan chasing after Dr. Palmer. The robot takes a shortcut through a forest and then leaps off a very tall cliff, but somehow Dr. Palmer's truck is directly below, driving at the bottom of the cliff, despite only driving off a couple of seconds ago. (00:13:30)
Other mistake: Charlie Brown asks Linus if everyone likes him for who he is, or who they think he is. A crowd of kids then starts to form around Charlie Brown, and a camera crew starts filming him, but the reflection in the camera lens is not backwards, and the kids behind him are also not present in the reflection. (00:44:35)
Other mistake: When Thomas leaves Knapford at the end of the special, a train is derailed at an adjacent platform.