NoneType is not iterable (aiohttp)

Description

Bot crashes on startup or during HTTP requests with 'NoneType is not iterable' traceback from inside aiohttp.

Cause

aiohttp version 3.10+ changed internal API behaviour that discord.py-self 2.1.0 depends on. Installing aiohttp without pinning the version pulls the latest which is incompatible.

Fix

Pin aiohttp to >=3.10 in requirements.txt and reinstall. If still failing, downgrade to aiohttp==3.9.5 as a last resort.

Code change

pip install aiohttp

pip install 'aiohttp>=3.10'