You've only posted the backtrace, not the full error message.
Then there is the full message?
Edit: I don´t know if it are relacionate with the mistake but i the golden pokeball when a pokemon can evolve
[2022-05-13 00:38:18 +0200]
[Pokémon Essentials version 19.1]
[v19.1 Hotfixes 1.0.7]
Exception: NameError
Message: undefined local variable or method `newspecies' for #<PokemonPartyScreen>
Backtrace:
[LA Party Evolver] LAEVO.rb:411:in `block (2 levels) in pbPokemonScreen'
080:MessageConfig:621:in `block in pbFadeOutInWithMusic'
080:MessageConfig:566:in `pbFadeOutIn'
080:MessageConfig:620:in `pbFadeOutInWithMusic'
[LA Party Evolver] LAEVO.rb:409:in `block in pbPokemonScreen'
[LA Party Evolver] LAEVO.rb:294:in `loop'
[LA Party Evolver] LAEVO.rb:294:in `pbPokemonScreen'
268:UI_PauseMenu:182:in `block (2 levels) in pbStartPokemonMenu'
080:MessageConfig:566:in `pbFadeOutIn'
268:UI_PauseMenu:179:in `block in pbStartPokemonMenu'