Film about a magic phrase to save magical creatures?

Okay so years ago my elementary school teacher made us watch this movie about two children. One was a little girl and the other was her little brother. They go (maybe on vacation?) with their parents to a dead relative’s house (maybe it was the grandma, I don’t remember clearly), where the little brother discovers the reòative’s old library. At this point I’m not sure if there were some toys who came to life or they were book characters, either way they explain to the boy that in order to continue to survive someone has to read a specific phrase that’s up there in the library. Before that the relative did it, but now it’s up to the child: the problem is that the little boy hasn’t learned to read yet! I don’t remember the middle of the film, but I remember clearly the ending: the characters are slowly disappearing, but in the last seconds the boy manages to read the phrase and everybody is saved.
Can anybody find the title? It’s been on my mind for hours.