Thats expected.
The player embeds the Twitch Website in an iFrame.
That iFrame may throw any or all sorts of kinds of errors. And you don’t have to worry about it.
It’s pretty “standard” when embedding stuff from other places for that to happen, and you just don’t need to worry about it.
Additionally see also:
Which may fix and/or break more stuff, or cause more or less errors in the console. Which you also don’t need to worry about.
Any errors the player throws are sandboxed to the iFrame and won’t effect the website you are embedding into