Telethon: TypeError: 'ChannelParticipants' object is not subscriptable

Code that causes the issue

    i = 0
    async for user in client.iter_participants(dialog):
        if not user.bot:
            DATA.update(
                {
                    i:{
                        'first_name': user.first_name,
                        'last_name': user.last_name,
                        'username': user.username,
                        'phone': user.phone,
                        'access_hash': user.access_hash,
                        'id': user.id
                    }
                }
            )
            i +=1

Traceback

Traceback (most recent call last):
  File ".\main.py", line 112, in <module>
    client.loop.run_until_complete(main())
  File "D:\python\lib\asyncio\base_events.py", line 616, in run_until_complete
    return future.result()
  File ".\main.py", line 54, in main
    async for user in client.iter_participants(dialog):
  File "D:\python\lib\site-packages\telethon\requestiter.py", line 74, in __anext__
    if await self._load_next_chunk():
  File "D:\python\lib\site-packages\telethon\client\chats.py", line 224, in _load_next_chunk
    participants = results[i]
TypeError: 'ChannelParticipants' object is not subscriptable

As same as 928, @Lonami referenced a solution in comment section which was The issue is fixed in the development version.

The issue appears to be persisting from 2018 until today, and development version seems not useful in this case. any solutions or replacements?