It sounds as though you might have tried tried these, but just in case: When you have a problem with one particular site, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site. (1) Bypass Firefox's Cache Use Ctrl+Shift+r to reload the page fresh from the server. (You also can clear Firefox's cache completely using: orange Firefox button ''or'' Tools menu > Options > Advanced On the Network mini-tab > Cached Web Content : "Clear Now") (2) Remove your google.com cookies (save any pending work first) using either of these: * While viewing a page on the site, right-click and choose View Page Info > Security > "View Cookies" * Alt+t (open the classic Tools menu) > Page Info > Security > "View Cookies" Then try reloading the page. Does that help? ---- Two other recent threads on this error on Gmail or Google login: * [https://support.mozilla.org/en-US/questions/938531 Firefox has detected that the server is redirecting the request for this address in a way that will never complete.] * [https://support.mozilla.org/en-US/questions/938097 Why can't I access gmail using Firefox?]