Title: AUTH_BYTES_INVALID on auth.ImportAuthorization during Client.get_file() / download_media() (session looks valid)

[LightMoon]

I’m seeing intermittent AUTH_BYTES_INVALID errors when downloading media using Pyrogram. The error happens inside Client.get_file() (triggered via download_media() / media-group processing) and is caused by auth.ImportAuthorization. After that, my own download wrapper fails because the expected temp file was never created.

This started happening while downloading media from a private channel, and only for certain music file contents.

Environment

Library: Pyrogram 2.3.68

Python: 3.11

Runtime: Docker container (Linux)

Account type: Bot (Bot token, not user)

Session storage: Default Pyrogram session (no custom ExportAuthorization/ImportAuthorization in my own code)

If you need more details (OS, Docker image, etc.) I can provide them.

media_bot-1  | [14-Nov-25 05:58:14 AM - INFO] - processMediaGroup() - Line 231: helpers.utils - Downloading media group with 2 items...
media_bot-1  | [14-Nov-25 05:58:18 AM - ERROR] - get_file() - Line 1367: pyrogram.client - Telegram says: [400 AUTH_BYTES_INVALID] (caused by "auth.ImportAuthorization") Pyrogram 2.3.68 thinks: The authorization bytes are invalid
media_bot-1  | Traceback (most recent call last):
media_bot-1  |   File "/usr/local/lib/python3.11/site-packages/pyrogram/client.py", line 1228, in get_file
media_bot-1  |     await session.invoke(
media_bot-1  |   File "/usr/local/lib/python3.11/site-packages/pyrogram/session/session.py", line 420, in invoke
media_bot-1  |     return await self.send(query, timeout=timeout)
media_bot-1  |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
media_bot-1  |   File "/usr/local/lib/python3.11/site-packages/pyrogram/session/session.py", line 377, in send
media_bot-1  |     RPCError.raise_it(result, type(data))
media_bot-1  |   File "/usr/local/lib/python3.11/site-packages/pyrogram/errors/rpc_error.py", line 93, in raise_it
media_bot-1  |     raise getattr(
media_bot-1  | pyrogram.errors.exceptions.bad_request_400.AuthBytesInvalid: Telegram says: [400 AUTH_BYTES_INVALID] (caused by "auth.ImportAuthorization") Pyrogram 2.3.68 thinks: The authorization bytes are invalid

[bisnuray]

Hey bro, I've never faced this issue. If you're using Telegram, knock me up here: @iSmartDev. I'll give you the update script to test if it works or not.

[bisnuray]

Bro update max_concurrent_transmissions=20 to max_concurrent_transmissions=1 for both the bot and user clients, and try it. Notify me if it works or not.

[LightMoon]

I eventually used another GitHub project to download the files I was after. Not sure if this is related, but I thought you might want to have a look: Dineshkarthik/telegram_media_downloader#507

[bisnuray]

However, I am not sure about this. After investigations, I found out why this issue happened.

The AUTH_BYTES_INVALID error is caused by concurrent download operations competing for DC authorization in your user session.

Pyrogram documentation say to use Defaults to 1.

[LightMoon]

I am sure that I ensured one instance was running with no concurrent download.