Unless Yahoo changed something, which certainly is possible, the suggested approach is the usual: 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. Alternately, you also can clear Firefox's cache completely using: "3-bar" menu button (or Tools menu) > Options > Advanced On the Network mini-tab > Cached Web Content : "Clear Now" If you have a large hard drive, this might take a few minutes. (2) Remove your Yahoo cookies (save any pending work first). 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" In the dialog that opens, you can remove your Yahoo cookies without affecting other sites. Then try reloading the page and logging back in. Any improvement? ---- To rule out extensions as a possible culprit, could you try the site in Firefox's Safe Mode? That's a standard diagnostic tool to bypass interference by extensions (and some custom settings). More info: [[Troubleshoot Firefox issues using Safe Mode]]. You can restart Firefox in Safe Mode using either * "3-bar" menu button > "?" button > Restart with Add-ons Disabled * Help menu > Restart with Add-ons Disabled ''Flash and other plugins still run in Safe Mode'' After Firefox closes, a small dialog should display. Click "Start in Safe Mode" (''not'' Reset) Any difference? ---- Some users have reported that older bookmarks or home pages do not redirect to the latest Yahoo server correctly. As a workaround, try accessing mail through the home page (www.yahoo.com or att.yahoo.com or whichever one it happens to be).