Bug at the old abandoned car

[anedra]

I'm stuck at the old abandoned car hidden object scene. I have to find the number ten (add 7 + 3 in the notebook), but the pencil has disappeared. The hints are pointing at the box containing a string of marbles. I already collected that, but the string has now reappeared. The marbles can be selected again, but they are now invisible until added to the string. Looks like I might have to restart the game.