Hi Having an ongoing problem for over 1 year now installing extensions can manually be done in my appdata (etc) profile extensions folder.. but comes up corrupt if I try to do it via add-ons manager. have tried turning off eset malwarebytes, totally uninstalled no traces, reinstalled , new profiles, about: config xpinsall signatures thing, firefox studies, systems time, Driving me crazy trying to fix it, Any help would be appreciated .. Cheers Kevin