http://kb.mozillazine.org/The_page_isn't_redirecting_properly Not Redirecting properly = cookies

You can remove all data stored in Firefox for a specific domain via "Forget About This Site" in the right-click context menu of an history entry ("History -> Show All History" or "View -> Sidebar -> History"). Using "Forget About This Site" will remove all data stored in Firefox for this domain like history and cookies and passwords and exceptions and cache, so be cautious. If you have a password or other data for that domain that you do not want to lose then make sure to backup this data or make a note. You can't recover from this 'forget' unless you have a backup of involved files. If you revisit a 'forgotten' website then data for that website will be saved once again. *https://support.mozilla.org/en-US/kb/delete-browsing-search-download-history-firefox ---- You can create a new profile to test if your current profile is causing the problem. See "Creating a profile": *https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems. *https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile Boot the computer in Windows Safe mode with network support to see if that has effect in case security software is causing problems. *https://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/ *https://www.7tutorials.com/4-ways-boot-safe-mode-windows-10