No, they're not. The log is absent of any error like before, which leads me to believe that the stack traces back too far for it to be recorded (the function causing the error is being called by a function within a function within a function, etc.). I'll see if I can trace it manually. The issue pertains to the 'is this city a colony check' - this check is invoked with the city already passed by another function, but in this case, the city info is not correctly being passed, so it is effectively asking 'is this nothing a colony', which returns the 'nil' error. I've set up a pre-caution to return false if there is nil, but this isn't ideal - because then what should be a colony might turn out not to be.