For all of those leaving bad reviews about Greasemonkey 4, it only works properly with FF57+. If you are using FF56 or lower, use version 3.17 and do not update. If you got automatically updated and things got broken, you can reinstall the old version by following this link: https://addons.vaultpit.io/firefox/downloads/file/736199/greasemonkey-3.17-fx.xpi?src=version-history . Once back on 3.17, make sure you go immediately into the add-ons manager and turn off automatic updates for this extension. Anthony, you may want to put this info up front on AMO.