There is a bug with loading at the moment.  If a game is loaded before the bookshelf puzzle is completed, the bookshelf will not move and you will be unable to progress.  Should you be able to complete the game without needing to revert to a save, you will have no issues.

I am currently working on a patch but I am unsure when this will be fixed, as I do not know why this issue is happening at the moment.

I apologize for the issues, but hopefully you can still enjoy the game for what it is.