Trying to reply to comments "crashes" page - Firefox 52

Was not happening a month or two ago when I last tried to do that. The page doesn't exactly crash, but redirects to a "Yikes something went wrong" page at the same URL. Also this forum is completely unusable in the same browser.

I know it's an old browser but it worked fine before, so...why u do dis?

I don't really care that much how you design your site - just detect browsers and load something that works.