Could it be that you only picked up enough plants for seven potions? That's an error that I'm aware of and haven't got to it yet (if you don't have enough plants, the game allows you to keep going but gives an error when you run out of plants).
Really? I'll try to reproduce the error right away. It would help me a lot if you could copy the error here or send it to me via email, to ertal77@hotmail.com, because it didn't appear in any of the betatesting plays.
