The other day I saw several threads where users said they could enable Yahoo for their current session, but when they closed the last Firefox window and started Firefox again, the extension was disabled. If you check the Add-ons page, is that the pattern you're seeing? Either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Extensions. Then check at the bottom of the list on the right side for a disabled Yahoo Toolbar extension and see whether you can enable it there.

Thank you. I did try that and several other things all without results. I did learn that both Firefox and Yahoo are working to resolve the issue. Thank you jscher2000 for taking the time to try to assist with this matter.

Okay, but just to get a full understanding of your situation, which is the best description:

• You cannot enable the Yahoo Toolbar ever
• You can only enable the Yahoo Toolbar by reinstalling it, using the Add-ons page doesn't work

If it can be enabled:

• You can enable the Yahoo Toolbar for your entire session, but it becomes disabled when you exit Firefox and start it up again
• You can enable the Yahoo Toolbar for a time, but it becomes disabled without ending the session (for no apparent reason)

Followup: The Yahoo toolbar add-on was updated on December 29, 2015. The latest version of the Yahoo toolbar fixes an issue that caused it to become disabled in Firefox 43.