What I was trying to do today was monkeypatch my Known site so that it used an updated version of fragmention rather than the old one on withknown.com. However, I typo'd the script include line so that it reads:
This manages to put the rest of the page inside a script tag and so became blank. Because known includes this header prefix in the editing pages too, I can't undo this mistake.
It also apparently breaks micropub posting, and certainly micropub auth and login.
I think I extended the meaning of Tantek's js;dr tonight anyway.
Update: thanks to Peter Molnar in irc for suggesting how to fix this with browser html hacking.