Hi, we checked and we didn't find any bugs in the offices near the painting, (the painting opens correctly after pressing the red button located in the locker in the director's room on the upper floor) we made the path and we arrived in the room taking the book without problems! The only thing you have to reinstall the game and try again, we reiterate that other people have played at that point and there is no bug!
I attach a video At 13:45: https://www.youtube.com/watch?v=t6wdEtwY8kU&list=PLjNN14-oTKLYK1PuhVyc1EDGweDkl7UqG&index=9