not in solo mode

Thanks! I think I know what caused the problem: I only had one player seated when I pressed the "setup" button. So now I'll make sure that everyone is seated before setup.
Fortunately it wasn't a problem during the game, because we just moved the secrets around between the rooms as we picked them up (and used cubes of an unused color to keep track of how many were left in each room) and we ended up not needing all of them.

Yeah secrets are placed as soon as you select the board, so players must have sit before this stage.