I've been seeing the same thing. I want this to work on my browser because it's wicked fast.

Getting the error with LibreWolf (FF w/tweaks and a ton of extensions) with only occasional success. Also the same error with Firefox (some extensions) but I have slightly more success.

Flashpeak Slimjet (Chrome, closed source): Some error msgs but mostly trying to load the video with no success (ie, "hourglass", no error msg).

No issues with Vivaldi (some extensions) & Brave (no extensions).