Image Insert is broken.
On firefox 65.0.2, win 10.
I just get a grayed-out image dialog box, that won't respond, to keyboard or mouse clicks. I have to click the Back button to get out, and I lose the thread post I was working on, too.
I'd post a screen shot, but I can't insert it, of course.
...And the thread posting box is pretty tiny on my 4K monitor, too, not scaled up like the rest of the BF pages.
(By the way, you've never fixed the "Indent" button. It makes a "<left>" style, instead of an "<indent>" style. This should have been trivial to fix, if anybody cared at all. It's been like this for more than year.)