When I look at the Area section of Pikachu's Pokedex entry I get this
Exception: NameError
Message: undefined local variable or method `mapppos' for #<PokemonNestMapScene:0x89c2368>
PokemonNestAndForm:58:in `pbStartScene'
PokemonNestAndForm:57:in `each'
PokemonNestAndForm:57:in `pbStartScene'
PokemonNestAndForm:51:in `each'
PokemonNestAndForm:51:in `pbStartScene'
PokemonNestAndForm:136:in `pbStartScreen'
PokemonPokedex:821:in `pbDexEntry'
PokemonPokedex:756:in `loop'
PokemonPokedex:828:in `pbDexEntry'
PokemonPokedex:755:in `pbActivateWindow'
Similar Happens with Chansey also and probably others. This is on a fresh Verison of Essentials