I'm sorry, but an uncaught exception occurred.

While running game code:
  File "game/script.rpy", line 301, in script
    $ show_moku("closed happy", shift)
  File "game/script.rpy", line 301, in <module>
    $ show_moku("closed happy", shift)
  File "game/layers.rpy", line 129, in show_moku
    renpy.show("moku " + " ".join(attrs), transition=transition)
TypeError: show() got an unexpected keyword argument 'transition'