[Error] Pokedex Error

Hey, I have a problem with the dex, can anyone help
Error:
---------------------------
Pokemon Inferno
---------------------------
[Pokémon Essentials version 17]

Exception: NoMethodError

Message: undefined method `[]' for nil:NilClass

PScreen_PokedexEntry:37:in `pbStartScene'

PScreen_PokedexEntry:562:in `pbStartScreen'

PScreen_PokedexMain:811:in `pbDexEntry'

PScreen_PokedexMain:1179:in `pbPokedex'

PScreen_PokedexMain:1155:in `loop'

PScreen_PokedexMain:1182:in `pbPokedex'

PScreen_PokedexMain:1154:in `pbActivateWindow'

PScreen_PokedexMain:1154:in `pbPokedex'

PScreen_PokedexMain:1196:in `pbStartScreen'

PScreen_PokedexMenu:126:in `pbStartScreen'

Thanks to anyone helping

Can you explain that in more detail?

Version 17 had A LOT of bugs which were fixed in 17.2. Update it first and see if the error persists.