The Icon of the forum has changed into something black and transparent. It is really hard to make out a Forum tab now if multiple tabs are open. Although… I must admit I am running darkmode.
The code view has a very fine font. Not really a code font… I really deeply dislike it, anybody else?
Not that I am aware. This is on my old MacBook Pro but I haven't changed anything there. AdBlocker is off… this is my console in Chrome. In Safari it is okay? Weird…
I'm not sure about the thin font weight, but I do see that the coloring/bolding is different in Safari, Chrome, and Firefox. Safari's rendering is definitely the most preferable.
I can't reproduce the manifest errors; it looks like your browser might have some preference set to be stricter than usual? Can you try going to chrome://flags/ and using reset all, as well as temporarily disabling any exceptions, and see if that helps after a relaunch?