[Scripting Question] Issues with encounter method (16.2)

[ArchyTheArc]

So been trying to set up headbutt tree encounters like in HGSS i've got the code for them to trigger all working its the encounter modifier side thats causing issues;

so the encounters scale to the parties level (with some randomness) and that part works fine; however
i'm trying to add code for the game to detect evolutions and evolve them;

Events.onWildPokemonCreate+=proc {|sender,e|
  pokemon=e[0]
  terrain=Kernel.pbFacingTerrainTag
  if PBTerrain.isHeadbuttable?(terrain) && 
      !pbGetMetadata($game_map.map_id,MetadataBicycleAlways)
    newlevel=pbBalancedLevel($Trainer.party) - 4 + rand(5)   # For variety
    newlevel=1 if newlevel<1
    newlevel=PBExperience::MAXLEVEL if newlevel>PBExperience::MAXLEVEL
    pokemon.level=newlevel
    pokemon.level=newlevel
    pokemon.calcStats
    pokemon.resetMoves
    terrain=Kernel.pbFacingTerrainTag
    if PBTerrain.isHeadbuttable?(terrain) && 
        !pbGetMetadata($game_map.map_id,MetadataBicycleAlways)
      evos=pbGetEvolvedFormData(pokemon.species)
      if evos && evos.length>0
        species=evos[rand(evos.length)][2]
        newspecies,newform=pbCheckEvolution(pokemon)
        #newspecies,newform=pbGetSpeciesFromSpecies(species)
        level=pbGetMinimumLevel(species)
        level=[level,pokemon.level].max
        #level+=rand(5)
        pokemon.species=newspecies
        pokemon.form=newform
        pokemon.level=level
        pokemon.name=PBSpecies.getName(newspecies)
        pokemon.calcStats
        pokemon.resetMoves
      elsif evos && evos.length==0 # no more evolutions
        for i in 0...6
          pokemon.iv[i]=31
        end
        pokemon.calcStats
      end
    end
  end
}

its based off another code (originally for 17.2 and downscaled to 16.2)

however the issue isn't evolving; as seen here

the pokemon can evolve fine its when they cant or dont evolve is the issue; with that latest code; this is the error i get;

Exception: Errno::EINVAL
Message: Invalid argument - Data/attacksRS.dat
File_Mixins:65:in `pos='
File_Mixins:65:in `getOffset'
PokeBattle_Pokemon:443:in `__mf_getMoveList'
Pokemon_MultipleForms:91:in `getMoveList'
PokeBattle_Pokemon:457:in `resetMoves'
PField_EncounterModifiers:135
PField_EncounterModifiers:107:in `call'
Event:54:in `trigger'
Event:49:in `each'
Event:49:in `trigger'

im guessing their is some issue with getting their attacks or something? sorry if its not much info nothing else has been changed towards this except some multiple form code.