For some reason Mu block origin, quit working today, adds on shows only "disable or remove" it's icon is missing from toolbar. Removed it & re-installed, same as above. Addon now say Legacy presume FF57 related. Ran KIS, HMP alert, & ADW scans clean KIS web anti-virus, complained every time I opened my home page KIS failed along with the other scans to stop this, ran CCleaner & it's reg cleaner, stopped the warnings. Why is it, it can find but can't stop the problem?