Does the form submit and return to the same page, or does the submit button seem completely dead?

A few thoughts:

(1) In past threads, Yahoo would not stay logged in with a particular connection setting. You can check that here:

"3-bar" menu button (or Tools menu) > Options > Advanced > Network mini-tab > "Settings" button

The "Auto-detect" setting causes problems with Yahoo (and sites on the AOL network). Try "No proxy" to see whether that works any better.

(2) Because Yahoo uses multiple subdomains (e.g., mail, login, www) you may need to allow "third party" cookies in order to stay logged in across Yahoo sites. This article describes where that is set: Websites say cookies are blocked - Unblock them.

(3) In case one of your extensions is involved, could you test the page in Firefox's Safe Mode? That's a standard diagnostic tool to deactivate extensions and some advanced features of Firefox. More info: Diagnose Firefox issues using Troubleshoot 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

Not all add-ons are disabled: Flash and other plugins still run

After Firefox shuts down, a small dialog should appear. Click "Start in Safe Mode" (not Reset).

Any difference?

the button is dead

also tried what you said still having issues the button is still dead

It sounds like you have covered all the bases. Could you watch for any error message that occurs when clicking the button. Here's how:

Open Firefox's Browser Console using either:

• Ctrl+Shift+j
• menu button > Developer > Browser Console
• (menu bar) Tools > Web Developer > Browser Console

At the top, click the Clear button to get rid of the clutter. Switch over to Yahoo and click the purple Login button. Then switch back to the console and check for any new messages. Do you see anything that looks like an error?