Following Pokemon 1.4.1

Every time i try start my game theres an error
this is what it says
Section400 1180 line in <class NameError occured.
undefined method access for class TrainerPC

Does anyone know how to fix this?

I'm not the only one who got in error method when applying this. Every time I've tried to add this to one of my games its caused an error. I actually got one of those games to play, but the pokemon simply weren't following me and it would crash when I tried to speak to the second event again. Even better, it would crash right after playing the lead (supposed to be following) pokemon's cry. Very creepypasta, I loved it. But it's not supposed to do that, I need the game to be useable.

I put the script into an unmodified version of V18, started a new game, and got the same error. here it is:
---------------------------
Pokemon Essentials
---------------------------
[Pokémon Essentials version 18.1]

Exception: NoMethodError

Message: undefined method `-' for nil:NilClass



Backtrace:

Following:656:in `talk_to_pokemon'

Following:1562:in `update'

Scene_Map:229:in `main'

Scene_Map:226:in `loop'

Scene_Map:231:in `main'

Main:45:in `mainFunctionDebug'

Main:24:in `mainFunction'

Main:24:in `pbCriticalCode'

Main:24:in `mainFunction'

Main:55