MFPCreateMediaPlayer returning uknown/undocumented error code 0x80070002 on call

In RPG Maker VX Ace, I'm attempting to write my own video player script out of complete boredom, however, I've run into a bit of a snag. When the game tries to call MFPCreateMediaPlayer from my script, it results in an error code(0x80070002 which doesn't exist in the full list of error codes documented here.

My current code in-script is

module Graphics
  MFPCreateMediaPlayer = Win32API.new("Mfplay", "MFPCreateMediaPlayer", "pilplp", "i")
  GetActiveWindow = Win32API.new("User32", "GetActiveWindow", [], "L")
  CreateWindowExA = Win32API.new("User32", "CreateWindowExA", "lppliiiillpp", "l")
  GetWindowLongA = Win32API.new("User32", "GetWindowLongA", "li", "l")
  class << self
    def play_movie(filename)
      @vp ||= {:buffer => [].pack('x') * 256}
      p MFPCreateMediaPlayer.call(File.dirname(__FILE__) + filename, 1, 0, nil, GetActiveWindow.call(), nil)
    end
  end
end

If there are any ideas as to what this means, it would be incredibly appreciated.

thank you!