I still don't understand which of my extensions stop this one from working, but some of them do. Disclaimer: by "stops this one from working" I mean that I can't log into Twitch and use chat with this extension's player. Sometimes, I turn off an extension, then this player starts working for a while, but then when I refresh the page this player stops working again. So, in the end, the choice is thus: you either use this extension and this extension only, OR you use anything and everything else. It's not for me. Twitch is just one of the websites I use, and I need my extensions for others.