[Error] Map Transfer Music Error

[Pe_Zero]

Hi there, I'm here to look for help, because I've experienced an error I haven't seen yet, and there doesn't seem to be any solution on the Internet.
I have no idea why, I didn't mess with scripts, but whenever I go from one connected map to another, I get this message

The line it refers to are these (I think):

Spoiler:

#===============================================================================
# Audio playing
#===============================================================================
def pbCueBGM(bgm,seconds,volume=nil,pitch=nil)
  return if !bgm
  bgm        = pbResolveAudioFile(bgm,volume,pitch)
  playingBGM = $game_system.playing_bgm
  if !playingBGM || playingBGM.name!=bgm.name || playingBGM.pitch!=bgm.pitch
    pbBGMFade(seconds)
    if !$PokemonTemp.cueFrames
      $PokemonTemp.cueFrames = (seconds*Graphics.frame_rate)*3/5
    end
    $PokemonTemp.cueBGM=bgm
  elsif playingBGM
    pbBGMPlay(bgm)
  end
end

[I]def pbAutoplayOnTransition
  surfbgm = pbGetMetadata(0,MetadataSurfBGM)
  if $PokemonGlobal.surfing && surfbgm
    pbBGMPlay(surfbgm)
  else
    $game_map.autoplayAsCue
  end
end[/I]

def pbAutoplayOnSave
  surfbgm = pbGetMetadata(0,MetadataSurfBGM)
  if $PokemonGlobal.surfing && surfbgm
    pbBGMPlay(surfbgm)
  else
    $game_map.autoplay
  end
end

Any idea how to fix it? Any help is appreciated ^^