Hi, try this signed Yahoo Toolbar add-on.

If you still need the Firefox menu bar (with File on it), right click in the tab bar - but not on a tab, and select Menu Bar.

If your question is resolved by this or another answer, please take a minute to let us know. Thank you.

i have tried repeatedly to re download signed yahoo toolbars. you completely ignore me and delete them. i want my yahoo toolbar left alone. i understand you think you know all but i want to KEEP my yahoo toolbar!!!!!!

windowguy28 said

i have tried repeatedly to re download signed yahoo toolbars. you completely ignore me and delete them. i want my yahoo toolbar left alone. i understand you think you know all but i want to KEEP my yahoo toolbar!!!!!!

The Yahoo toolbar add-on becoming disabled in Firefox 43 is a known issue that Mozilla and Yahoo are working on. In this particular case you can follow the instructions for advanced users in the Add-on signing in Firefox article (toggle the xpinstall.signatures.required preference to false in the Firefox configuration Editor) but this is only a temporary solution which will no longer work in Firefox 44 future Firefox versions.

You are replying to a solved thread. If you need more help you'll need to ask your own question. See Mozilla Support rules and guidelines.

Followup: There's been an update to the Yahoo toolbar add-on that resolves the problem. If you have set the xpinstall.signatures.required preference to false in the Firefox Configuration Editor (about:config page) as a workaround, you can go back now and reset the preference to true.