Make sure your not using Private Browsing Mode.

Firefox Menu > Options > Options > Privacy

• History > Firefox Will > Choose "Use Custom Settings for History"
  • check[x] Accept cookies from sites
  • Click Exception > Make sure yahoo.com/yahoomail.com is not in exception list.

If hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Firefox uses the about: protocol to access built-in about: pages that you can open via the location bar just like you open web pages.

http://kb.mozillazine.org/About_protocol_links).

Do NOT click the Reset button on the Safe Mode start window or otherwise make changes.

If clearing cookies doesn't work then it is possible that the cookies.sqlite file that stores the cookies is corrupted.

Rename (or delete) cookies.sqlite (cookies.sqlite.old) and delete other present cookie files like cookies.sqlite-journal in the Firefox profile folder in case the file cookies.sqlite got corrupted.

http://kb.mozillazine.org/Cookies

https://support.mozilla.org/kb/Deleting+cookies

Thank you.

Check the connection settings.

• Tools > Options > Advanced > Network : Connection > Settings
• https://support.mozilla.org/kb/Options+window+-+Advanced+panel

If you do not need to use a proxy to connect to internet then try to select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly.

See "Firefox connection settings":

• https://support.mozilla.org/kb/Firefox+cannot+load+websites+but+other+programs+can

Yahoo has moved some accounts between different servers as part of its Neo update. If you are using an old bookmark to access your mail, it might not be redirecting correctly.

Try accessing your mail either through the Yahoo home page or My Yahoo! page, or using a more generic address and see whether that works any better:

• https://www.yahoo.com/
• https://my.yahoo.com/
• https://mail.yahoo.com/

Thanks everyone.

The solution was decidedly low-tech. As has happened in the past with Yahoo Mail over the past year or so (couldn't upload files, couldn't add addresses from contact list, etc.) all I had to do was leave it be for a day or so. Seems the gremlins get bored after a while and the problem resolves itself.

I guess I need to take a slightly more zen approach to these little hiccups before announcing the sky is falling.

For others that get this:

- my cookie permission settings were fine (and had not changed prior to the problem) and I have FF set to clear every time I close the browser. - NO PROXY setting was already on - I was not operating in Private Browsing mode.

Thanks Again.