hello, does it work when you access yahoo mail through this link?: https://mail.yahoo.com/

please also try to clear the cache & cookies from yahoo.com and reload the page.

Having exactly same problem, happened only past few days. This is either Yahoo or Firefox problem. nothing to do with clear cache or cookies kind of thing. IE works just fine. Firefox forever error: 3. Please fix this if possible i hope this is not yahoo issue.

In case you use a bookmark to reach the mail page then try to navigate to the mail page starting with the site's main page or its log in page.

You can remove all data stored in Firefox from 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") or via the about:permissions page.

Using "Forget About This Site" will remove all data stored in Firefox from that domain like bookmarks, cookies, passwords, cache, history, and exceptions, so be cautious and if you have a password or other data from that domain that you do not want to lose then make a note of those passwords and bookmarks.

You can't recover from this 'forget' unless you have a backup of the involved files.

It doesn't have any lasting effect, so if you revisit such a 'forgotten' website then data from that website will be saved once again.

You can also check the cookie permissions.

• Tools > Options > Privacy > Firefox will: "Use custom settings for history"