Lia at midnight glitched and I cannot find anything to get the key from the cylinder or find any keys
If you go to the paint room on the right hand cupboard, or around there you will be prompted to open a padlock - the code is 951 (can see it in the back of a painting in the room) and you will get dentist tool - then go to cylinder and use the dentist tool to get the key to open lia's door in the morning
Edit: Just to warn you for the morning, if you go to lia after opening the door and do the erotic option to fuck, your passion afterwards will be reset to 0 - one of the bugs in the game