Blocks disappearing

I have a student (username 25schmidte) who has a project "drawing village" that she was working on in class yesterday and after school yesterday (sometime after 2:30pm?) and she had made a lot of custom blocks such as "draw window" and "draw door" but now when she opens the project she doesn't see those custom blocks anymore. She is very confident that she saved her work yesterday. I asked her to recover the project but that doesn't seem to have done anything.

Any idea why this could be happening?