Event handler exception massive spam

Created by: Lymdun

Summary

My console is being flooded of event handler exception for no reason. Mostly of MESSAGE_REACTION_ADDED even nothing in my code is using reactions.

Details

First of all, I've confirmed that the bug is not coming from my code on the Discord server. As a proof, it happens even when no commands are registered at all. It also happens when setting UseDefaultCommandHandler as true. Also, as you can read on the stacktrace, it is pointing internal code (defined in [...]). Stacktrace: https://pastebin.com/W4pUHwt7 Code example: https://pastebin.com/NyBYBhKF

I'm using Net5.0, but it was also happening on Net core 3.1. The MESSAGE_REACTION_ADDED exceptions are happening only when shards are booting up.

Notes

It might be related, but I'm getting a lot of errors about MESSAGE_CREATED exception when I'm using my own async handler for MessageCreated, even though everything is wrapped on a Task.Run. (And occurs even when all shards are loaded) Only happens on Linux Debian 10 production machine. Works perfectly fine on Windows. I know you would want a repro project, but it seems to happens only when lot of shards & guilds are being loaded up. (In my case, 70k guilds & 40 shards)