Error when starting up the game.

[HighTomTitty]

___________________________________________
ERROR in
action number 1
of Other Event: Game Start
for object GUI_MainTitle:

Error defining an external function.


Don't understand what it means, I downloaded some custom sprites and made a ship with them... They worked perfectly in the ship maker, but I get this error message when starting up the game with the Custom ship.

The game worked perfectly fine moments ago when I didn't have the sprites installed. Anyone know what's happening?