"list index out of range" error when connecting to voice channel

[siyukatu]

Summary

Unable to connect to voice channel due to "list index out of range" error

Reproduction Steps

It occurs only rarely, so the pattern is unclear.
It depends on the data sent from the Discord server.

Minimal Reproducible Code

import discord

intents = discord.Intents.none()
intents.guilds = True
intents.message_content = True
intents.guild_messages = True
intents.voice_states = True
bot = discord.Bot(intents=intents)

@bot.event
async def on_message(message):
    if message.content == "connect":
        await message.author.voice.channel.connect()

bot.run("TOKEN")

Expected Results

Connected to voice channel

Actual Results

[DEBUG] discord.gateway: Voice websocket frame received: {'op': 8, 'd': {'v': 4, 'heartbeat_interval': 13750.0}}
[DEBUG] discord.gateway: Voice websocket frame received: {'op': 2, 'd': {'streams': [{'type': 'video', 'ssrc': 193186, 'rtx_ssrc': 193187, 'rid': '', 'quality': 0, 'active': False}], 'ssrc': 193185, 'port': 50002, 'modes': ['aead_aes256_gcm_rtpsize', 'aead_xchacha20_poly1305_rtpsize'], 'ip': '35.213.101.214', 'experiments': ['fixed_keyframe_interval']}}
[DEBUG] discord.gateway: received packet in initial_connection: b'(hidden)'
[DEBUG] discord.gateway: detected ip: (hidden) port: (hidden)
[DEBUG] discord.gateway: received supported encryption modes:
[ERROR] __main__: list index out of range
Traceback (most recent call last):
  File "/home/ubuntu/test/vc_test.py", line xxx, in connect_vc
    await target.connect(timeout=10, reconnect=True)
  File "/usr/local/lib/python3.11/dist-packages/discord/abc.py", line 1994, in connect
    await voice.connect(timeout=timeout, reconnect=reconnect)
  File "/usr/local/lib/python3.11/dist-packages/discord/voice_client.py", line 404, in connect
    self.ws = await self.connect_websocket()
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/dist-packages/discord/voice_client.py", line 375, in connect_websocket
    await ws.poll_event()
  File "/usr/local/lib/python3.11/dist-packages/discord/gateway.py", line 945, in poll_event
    await self.received_message(utils._from_json(msg.data))
  File "/usr/local/lib/python3.11/dist-packages/discord/gateway.py", line 862, in received_message
    await self.initial_connection(data)
  File "/usr/local/lib/python3.11/dist-packages/discord/gateway.py", line 916, in initial_connection
    mode = modes[0]
           ~~~~~^^^
IndexError: list index out of range

Intents

guilds, message_content, guild_messages, voice_states

System Information

• Python v3.11.11-final
• py-cord v2.6.1-final
• aiohttp v3.11.13
• system info: Linux 6.8.0-55-generic # 57-Ubuntu SMP PREEMPT_DYNAMIC Wed Feb 12 23:42:21 UTC 2025

Checklist

• I have searched the open issues for duplicates.
• I have shown the entire traceback, if possible.
• I have removed my token from display, if visible.

Additional Context

No response

[riro110]

This issue still occurs.
#2651 seems to be trying to resolve this issue.

[siyukatu]

@Lulalaby

This issue mentions that modes (supported encryption modes) is empty.
#2800 fixes another "IndexError". However, I don't think this will solve the problem.

[asadfgglie]

@Lulalaby

This issue mentions that modes (supported encryption modes) is empty. #2800 fixes another "IndexError". However, I don't think this will solve the problem.

The problem is still not solved, as mentioned above.

[PWDSerialgamer07]

Any update on this?

[Paillat-dev]

@PWDSerialgamer07 Should be fixed on master, pip install -U git+https://github.com/Pycord-Development/pycord, If you have an issue feel free to open another issue.

[CoreTaxxe]

Any update on this?

Master did not work for me for some reason but you can install from this pr as a bandaid fix. pip install git+https://github.com/Pycord-Development/pycord.git@refs/pull/2651/head

[Paillat-dev]

@PWDSerialgamer07 / @CoreTaxxe If you have a bug that is not fixed on master, could you please open a new issue with the corressponding full traceback and a minimal reproducible example ? That will help getting things fixed.

Also, please try using pull request #2651 since some users mentioned it fixing this issue with pip install git+https://github.com/Pycord-Development/pycord.git@refs/pull/2651/head

Thx !