Discord changed the channel-overwrites object on their side, which broke older discord.py installs with the deny_new keyword error. The fix is to upgrade the library: run pip install -U discord.py. When a Discord bot breaks overnight with no code change, check for a library or API-side change first instead of debugging your own code, and keep discord.py pinned to a recent version.

Context: Stack Overflow #63027848 (top answer, 71 votes): A working discord.py bot suddenly started throwing TypeError about an unexpected keyword argument deny_new with no code changes on the reporter's side. The breakage appeared after a failed hosting attempt, which made it look environment-related, but the actual cause was upstream.