All pages loading forever in Firefox 53

[ETHproductions]

In Firefox 53, every page I can think of on the domains https://codegolf.stackexchange.com and https://codegolf.meta.stackexchange.com, with the exception of https://codegolf.stackexchange.com/reputation, seems to load forever when the userscript is on. The content loads completely AFAICT, but Firefox keeps displaying the loading icon indefinitely.

This happens on:

• Firefox 53.0.3 with Greasemonkey
• Firefox 53.0.3 with Tampermonkey

This does not happen on:

• Firefox 54.0a2 with Greasemonkey
• Firefox 54.0a12 with Greasemonkey (I can't get Tampermonkey to work with Firefox Developer Edition)
• Chrome 58.0.3029.110 with Tampermonkey
• All versions with the userscript turned off

Perhaps it's just some bug with Firefox 53, but I'm not experienced enough to know how to track down the problem.

[ETHproductions]

This isn't happening any more, I wonder what was wrong...