I have a code which works fine on the Simulation Survival room but not on the 2 player room. On the 2 player room, the code works well for my creeps but for Player 2 not, I get following error:

TypeError: Cannot read property 'main' of undefined
at n (blob:https%3A//screeps.com/1d97fc9f-51bb-498d-8cac-817d59274859:5:27831)
at Object.c.runCode (blob:https%3A//screeps.com/1d97fc9f-51bb-498d-8cac-817d59274859:6:33)
at DedicatedWorkerGlobalScope.self.onmessage (blob:https%3A//screeps.com/1d97fc9f-51bb-498d-8cac-817d59274859:5:4814)


All clear, thanks!

Which is the role of the source keeper? is there anything in the ducumentation about it?