Получаю ошибку "unmatched group" при get_post_audio

[whakru]

Окружение

vk_api: 11.9.1

Пример

login, password = 'login', 'parol'
	vk_session = vk_api.VkApi(login, password)
	try:
		vk_session.auth(token_only=True)
	except vk_api.AuthError as error_msg:
		print(error_msg)
		return

	vk_audio = audio.VkAudio(vk_session)



	vksad = vk_audio.get_post_audio(-id, post)
	print ''.join(vksad)

Получаю

Traceback (most recent call last):
  File "get.py", line 31, in <module>
    main()
  File "get.py", line 25, in main
    print ''.join(vksad)
  File "D:\Python27\lib\site-packages\vk_api\audio.py", line 635, in scrap_tracks
    link = RE_M3U8_TO_MP3.sub(r'\1/\2.mp3', link)
  File "D:\Python27\lib\re.py", line 291, in filter
    return sre_parse.expand_template(template, match)
  File "D:\Python27\lib\sre_parse.py", line 859, in expand_template
    raise error, "unmatched group"
sre_constants.error: unmatched group

Что я делаю не так? извините новичок в питоне =)