There are a couple of places where timing errors happen and result in various "Error (0)" messages:
If two people try to pet or water a tree at the same time, one will get an "Error (0): Verb not supported".
In Hell, if you click too rapidly on the grapes, you're given an option to squish the grape again even after it disappears, and then you get an error message (I don't remember the exact wording).