Ersetz das mal hiermit und schau ob es dann tut:
Code:
class Window_MapName < Window_Base
  def refresh
    contents.clear
    unless $game_map.display_name.empty?
      tmap_name = $game_map.display_name
      tmap_name = tmap_name.gsub(/\\V\[(\d+)\]/i) { $game_variables[$1.to_i].to_s }
      draw_background(contents.rect)
      draw_text(contents.rect, tmap_name, 1)
    end
  end
end