This will disable add-on signature enforcement; Enter about:config into your Firefox address bar Click the I'll be careful button Find xpinstall.signatures.required in the list Right click the preference Select Toggle until the value is false https://support.mozilla.org/en-US/kb/add-on-signing-in-firefox

https://wiki.mozilla.org/Firefox/AddOns/Status/Updates#Exec_Summary “Currently targeting Signing with no pref to turn off in Firefox 47”

thanks so much for trying but firefox still is not cooperating with Kaspersky. i will double check all my work but i'm pretty sure i did what you suggested and firefox still disables kaspersky and constantly asks for windows 7 updates. silently screaming..... happy new year

Remove Kaspersky. Reboot the computer, then run a registry scanner. After, download and install the current full installer.

I've called the big guys to help you. Good luck.