I got stuck after I escaped from the wolf / dog monster, in the hallway near the dormitories. When I tried to return to the dormatories, it said I didn't need to go there, or something like that, and I explored the whole area but none of the other doors could be interacted with at all.
There is a secret door inside the classroom where you encountered Lita, the red haired girl. You can open the secret door with the ID-Card you found inside the dormitories. In the new version, Lita gives a hint about that door