Separate Security Issue, please update your Flash 28.0 r0 by removing it with this tool : https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html If you use it Reinstall with Flash Player Version: 30.0.0.154 Current Version https://get.adobe.com/flashplayer/otherversions/ Step 1: Select Operating System Step 2: Select A Version (Firefox, . . . .) Note: Other software is offered in the download. <Windows Only>

Please note : Firefox 52.9.0esr is the last browser available for XP/VISTA that will compatible. Do not download anything higher as will cause issues.

Note : No further Support for XP/VISTA after month end.

Please update your expired OS to keep yourself and Others safe.

Hi, So that is out of the way. As Firefox is not a Email Client, where are you getting Error 15 from ?

ntil1947 said

I can access web sites and news stories but the email access won't open, just a blank page with error 15.

Error 15 - that is Yahoo

Please see : https://help.yahoo.com/kb/SLN3549.html