How do you get out of the charms class cellar in Lego Harry Potter years 1-4?

Answer 1

The room glitches if you jump onto the dragon too soon. To get out, you have to start the whole game again.

Answer 2

On the shelves to your right, there should be a purple container, WiLe that onto the purple side of the scales blocking to door.

Answer 3

you need to learn the charm and find the object he tells you to find and use that spell the object should be glowing green