Plot hole: When Charlotte kissed Naveen at the end, she should've turned into a frog as well because she was no longer a princess.
Suggested correction: When ordinary people kiss a frog, they don't transform into anything. (Perhaps they die from infection after a few days.) Charlotte was just an ordinary person. Tiana was chosen. She wished upon the star. Naveen and the consequences of kissing Naveen were a result of Tiana's wish.
Suggested correction: How? She was no longer a princess.
Tiana turned into a frog because she kissed Naveen without being a princess, so Charlotte should have, too.
Tiana broke the talisman that the voodoo man had, thus breaking any more frog-turning spell. I know Mama Odie said that Naveen and Tiana broke the spell when they got married, but Dr. Facilier was still responsible for the spell in the first place, and he died, so there's that.
Plot hole: After the dinosaur kids wrecked the playground, Manny tells Sid, "Whatever they are, take them back" and someone says "What are they?" as well. Later, when Mummy Dinosaur appears, Ellie says, "I thought those guys were extinct!" and one minute later Manny says, "She's a dinosaur!" How could they possibly not see that the kids were dinosaurs if they already knew about dinosaurs in the first place?
Suggested correction: They weren't sure about the baby dinosaurs' species because dinosaurs were thought to be extinct. The mother dinosaur eventually showing up, with her more convincing dinosaur properties of being much larger and menacing-looking, convinces them otherwise.
Plot hole: The main character never takes the elevator. He only takes the stairs. When leading a workshop he leads a group of people from street level by saying 'follow me' and in the next shot the whole group is on top of a high rise hotel. How did he and the entire group get from street level to the roof together if he never takes the elevator?
Plot hole: Mr. Cranston asks Denise to be the accompanist for the school's production of "Chicago". This is an error. In the year 2009, in which the film is set, this would be impossible since the licensing company which has the theatrical rights for "Chicago" restricts the show from being produced (even by amateur groups and schools) anywhere in the greater New York area while there is an open-ended production running on Broadway.