What OS? Show the issue and provide screenshots and steps to replicate. Do you have the same issue with Firefox in [https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#w_how-to-start-firefox-in-4troubleshoot-modesf5safe-modesf Troubleshoot Mode]? Did you try clearing the browser cache? https://support.mozilla.org/en-US/kb/how-clear-firefox-cache# You can try to clear all items for a single site. https://support.mozilla.org/en-US/kb/remove-websites-address-bar-suggestions I don't do social media, but gmail works for me.

Clearing cache did not fix issue. When starting in troubleshooting mode i do not get that warning.

You have to figure out which add-on is causing the issue. May the Schwartz be with you.

User Agent Switcher was the culprit.