The server sent an unknown constructor

[vedma1337]

Checklist

• I am sure the error is coming from Pyrogram's code and not elsewhere
• I have searched in the issue tracker for similar bug reports, including closed ones
• I ran pip3 install https://github.com/TelegramPlayground/pyrogram/archive/dev.zip --force-reinstall and reproduced the issue using the latest development version

Description

With any code after 10-15 seconds of userbot running it will start giving errors like this:
ValueError: The server sent an unknown constructor:

Steps to reproduce

1. Launch userbot
2. Wait 10-15 seconds
3. Get an error flooded

Code example

from pyrogram import Client, filters

app = Client("session")

@app.on_message(filters.private)
async def hello(client, message):
    await message.reply("Hello from Pyrogram!")

app.run()

Logs

2025-05-10 21:40:22,359 - pyrogram.connection.connection - INFO - Connecting...
2025-05-10 21:40:22,460 - pyrogram.connection.connection - INFO - Connected! Production DC2 - IPv4 - TCPAbridgedO
2025-05-10 21:40:22,461 - pyrogram.session.session - INFO - NetworkTask started
2025-05-10 21:40:22,887 - pyrogram.session.session - INFO - Session initialized: Layer 203
2025-05-10 21:40:22,887 - pyrogram.session.session - INFO - Device: CPython 3.13.2 - Pyrogram 2.2.12
2025-05-10 21:40:22,888 - pyrogram.session.session - INFO - System: Windows 10 (EN)
2025-05-10 21:40:22,888 - pyrogram.session.session - INFO - Session started
2025-05-10 21:40:22,890 - pyrogram.session.session - INFO - PingTask started
2025-05-10 21:40:23,306 - pyrogram.dispatcher - INFO - Started 12 HandlerTasks
2025-05-10 21:40:24,431 - asyncio - ERROR - Task exception was never retrieved
future: <Task finished name='Task-34' coro=<Session.handle_packet() done, defined at C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\session\session.py:201> exception=ValueError('The server sent an unknown constructor: 0x5c62d151\nceaf5e4f 8c2ef1bf 4a1d6eb9 d996e151 9319c118')>
Traceback (most recent call last):
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\crypto\mtproto.py", line 70, in unpack
    message = Message.read(data)
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\message.py", line 46, in read
    return Message(TLObject.read(BytesIO(body)), msg_id, seq_no, length)
                   ~~~~~~~~~~~~~^^^^^^^^^^^^^^^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\tl_object.py", line 33, in read
    return cast(TLObject, objects[int.from_bytes(b.read(4), "little")]).read(b, *args)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\types\updates_t.py", line 200, in read
    updates = TLObject.read(b)
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\tl_object.py", line 33, in read
    return cast(TLObject, objects[int.from_bytes(b.read(4), "little")]).read(b, *args)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\primitives\vector.py", line 65, in read
    return List(
        t.read(data) if t
        else Vector.read_bare(data, size)
        for _ in range(count)
    )
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\primitives\vector.py", line 67, in <genexpr>       
    else Vector.read_bare(data, size)
         ~~~~~~~~~~~~~~~~^^^^^^^^^^^^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\primitives\vector.py", line 56, in read_bare       
    return TLObject.read(b)
           ~~~~~~~~~~~~~^^^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\tl_object.py", line 33, in read
    return cast(TLObject, objects[int.from_bytes(b.read(4), "little")]).read(b, *args)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\types\update_new_channel_message.py", line 68, in read  
    message = TLObject.read(b)
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\tl_object.py", line 33, in read
    return cast(TLObject, objects[int.from_bytes(b.read(4), "little")]).read(b, *args)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\types\message.py", line 255, in read
    media = TLObject.read(b) if flags & (1 << 9) else None
            ~~~~~~~~~~~~~^^^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\tl_object.py", line 33, in read
    return cast(TLObject, objects[int.from_bytes(b.read(4), "little")]).read(b, *args)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\types\message_media_web_page.py", line 91, in read      
    webpage = TLObject.read(b)
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\tl_object.py", line 33, in read
    return cast(TLObject, objects[int.from_bytes(b.read(4), "little")]).read(b, *args)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\types\web_page.py", line 163, in read
    attributes = TLObject.read(b) if flags & (1 << 12) else []
                 ~~~~~~~~~~~~~^^^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\tl_object.py", line 33, in read
    return cast(TLObject, objects[int.from_bytes(b.read(4), "little")]).read(b, *args)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\primitives\vector.py", line 65, in read
    return List(
        t.read(data) if t
        else Vector.read_bare(data, size)
        for _ in range(count)
    )
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\primitives\vector.py", line 67, in <genexpr>       
    else Vector.read_bare(data, size)
         ~~~~~~~~~~~~~~~~^^^^^^^^^^^^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\primitives\vector.py", line 56, in read_bare       
    return TLObject.read(b)
           ~~~~~~~~~~~~~^^^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\tl_object.py", line 33, in read
    return cast(TLObject, objects[int.from_bytes(b.read(4), "little")]).read(b, *args)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\types\web_page_attribute_unique_star_gift.py", line 60, 
in read
    gift = TLObject.read(b)
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\raw\core\tl_object.py", line 33, in read
    return cast(TLObject, objects[int.from_bytes(b.read(4), "little")]).read(b, *args)
                          ~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
KeyError: 1549979985

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\session\session.py", line 203, in handle_packet
    data = await self.loop.run_in_executor(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    ...<7 lines>...
    )
    ^
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\concurrent\futures\thread.py", line 59, in run
    result = self.fn(*self.args, **self.kwargs)
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python313\Lib\site-packages\pyrogram\crypto\mtproto.py", line 81, in unpack
    raise ValueError(f"The server sent an unknown constructor: {hex(e.args[0])}\n{left}")
ValueError: The server sent an unknown constructor: 0x5c62d151
ceaf5e4f 8c2ef1bf 4a1d6eb9 d996e151 9319c118
2025-05-10 21:40:28,049 - pyrogram.methods.utilities.idle - INFO - Stop signal received (SIGINT). Exiting...
2025-05-10 21:40:28,053 - pyrogram.dispatcher - INFO - Stopped 12 HandlerTasks
2025-05-10 21:40:28,053 - pyrogram.session.session - INFO - PingTask stopped
2025-05-10 21:40:28,053 - pyrogram.connection.connection - INFO - Disconnected
2025-05-10 21:40:28,054 - pyrogram.session.session - INFO - NetworkTask stopped
2025-05-10 21:40:28,054 - pyrogram.session.session - INFO - Session stopped

[righteon]

I didnt want to open another issue yet, but I also get a similar error.
It happens only for some messages - but I noticed it only happens with messages that are replies.

I also tried other forks of pyrogram (after pyrogram development stopped) and I get this same error. Im not deep enough into the Telegram API to know what this could be about but it seems that Telegram sends something that all the pyrogram forks can not interpret.

My bot has been working flawlessly for over two years and just recently started showing this problem - which leads me to believe something happened with the API.
If this cant be fixed I have to swtich to a different telegram bot library :/ So fingers crossed!

Here is the error Im getting:

future: <Task finished name='Task-63336' coro=<Session.handle_packet() done, defined at /home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/session/session.py:201> exception=ValueError('The server sent an unknown constructor: 0xafbc09db\n47bd268a 37037d2c fcb0a999 6e601876 05808606')>
Traceback (most recent call last):
  File "/home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/mtproto.py", line 70, in unpack
    message = Message.read(data)
  File "/home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/raw/core/message.py", line 46, in read
    return Message(TLObject.read(BytesIO(body)), msg_id, seq_no, length)
  File "/home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/raw/core/tl_object.py", line 33, in read
    return cast(TLObject, objects[int.from_bytes(b.read(4), "little")]).read(b, *args)
  File "/home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/raw/types/updates_t.py", line 203, in read
    updates = TLObject.read(b)
  File "/home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/raw/core/tl_object.py", line 33, in read
    return cast(TLObject, objects[int.from_bytes(b.read(4), "little")]).read(b, *args)
  File "/home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/raw/core/primitives/vector.py", line 65, in read
    return List(
  File "/home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/raw/core/primitives/vector.py", line 67, in <genexpr>
    else Vector.read_bare(data, size)
  File "/home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/raw/core/primitives/vector.py", line 56, in read_bare
    return TLObject.read(b)
  File "/home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/raw/core/tl_object.py", line 33, in read
    return cast(TLObject, objects[int.from_bytes(b.read(4), "little")]).read(b, *args)
  File "/home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/raw/types/update_edit_channel_message.py", line 68, in read
    message = TLObject.read(b)
  File "/home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/raw/core/tl_object.py", line 33, in read
    return cast(TLObject, objects[int.from_bytes(b.read(4), "little")]).read(b, *args)
  File "/home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/raw/types/message.py", line 263, in read
    reply_to = TLObject.read(b) if flags & (1 << 3) else None
  File "/home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/raw/core/tl_object.py", line 33, in read
    return cast(TLObject, objects[int.from_bytes(b.read(4), "little")]).read(b, *args)
KeyError: 2948336091

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/session/session.py", line 203, in handle_packet
    data = await self.loop.run_in_executor(
  File "/usr/lib/python3.9/concurrent/futures/thread.py", line 58, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/home/user/workspace/tg_bot/venv/lib/python3.9/site-packages/pyrogram/mtproto.py", line 81, in unpack
    raise ValueError(f"The server sent an unknown constructor: {hex(e.args[0])}\n{left}")
ValueError: The server sent an unknown constructor: 0xafbc09db
47bd268a 37037d2c fcb0a999 6e601876 05808606```