@Makyen Violentmonkey Firefox userscript issues: Workaround: in Violentmonkey's "Advanced" settings, check "Synchronous page mode" checkbox. Known fix: downgrade to the prior version and disable Violentmonkey updates in about:addons. More detail: The recently-updated, current version of Violentmonkey, 2.13.5, has issues with loading userscripts in page mode, which is how most userscripts need to be loaded, due to how most userscripts' are written. The workaround of checking the "Synchronous page mode" checkbox resolved the issues in limited testing, but more testing is needed to be sure that's really sufficient. It is known that downgrading your copy of Violentmonkey to the prior version, 2.12.13, will solve the issue. The most recent older version, 2.12.13, can be downloaded from here for Firefox. You can see all released versions of Violentmonkey for Firefox on addons.mozilla.org. If you downgrade, you will probably want to disable automatic updates for Violentmonkey from Violentmonkey's extension configuration page which you can access from about:addons. [This has been edited to remove an inaccurate explanation and to provide the workaround that doesn't require downgrading.]