Plot hole: After Max and Allison rescue Dani from the witches, Max is driving his parents' car. Winifred flies up along side of them and asks Max to show her his driver's permit. How would she know about driving permits, since she's been dead for 300 years?
Other mistake: After the Sanderson sisters are done sucking the life out of Emily Binx, they do a little dance thing after they become younger. When either Winifred or Mary swings past her, Emily's leg moves even though she's supposed to be dead. She's also playing with her hands and bobbing her head.
Continuity mistake: At the beginning of the movie, after the witches suck the life out of Emily, Winifred looks in a mirror and says, "Well...younger," and her green cape with a hood is on her in the closeup. In the next shot, when she says, "But, it's a start," she is not wearing her cape at all. (00:07:00)
Continuity mistake: When Max and Allison rescue Dani from the witches' house, they turn on the car lights to trick the witches into thinking it is daylight. After they get in the car and drive off, the same light that was supposed to have come from the headlight is still shining after they have left.
Factual error: The Sanderson House had been turned into a museum complete with a gift counter. The museum had been closed for years (note the dust and spider webs). The fluid in the lighter Max gets would have evaporated after a few months as Zippos are not airtight like a plastic disposable lighter would be.
Continuity mistake: When Winifred turns to stone in the graveyard, her fingernails rip shreds of cloth off of Max's sweatshirt (you can see them when he falls). Exactly one minute later, when he is lying down next to Dani and talking to her, it is clear that his sweatshirt is merely ripped, not shredded. (01:28:35)
Continuity mistake: When the witches take Dani back to the museum, the rope they use to tie her up with changes from shot to shot. First it's up around her neck, then it's around her chest.
Factual error: When the witches follow Mary into the alley after singing I Put A Spell On You, Mary Sanderson said she smelled Scrod, a bottom feeder that would be good with margarine. 300 years prior to that, butter would be the topping of choice as margarine hadn't been invented until the 1800s, when the sisters were dead.
Continuity mistake: When the Sanderson sisters get on the bus, the headlights on the bus are on because it is dark out. They are visibly on at that point and as well as when the bus runs over Binx but, when the sisters get off of the bus, the lights are not on (it is still dark out and it is only a few minutes later). If the bus was merely letting them off (which it was, it drove away a few seconds later), why were the lights turned off? (00:48:06)