SEC_ERROR_UNKNOWN_ISSUER

For the last month or so I find myself for a short time that all websites produce this error in Firefox. I always have the latest version of FF and I’m using the latest version of Windows 10.

If I turn of web shield then I can view the websites normally. The problem normally goes away at some point during the day.

  • Which Avast…? (Free/Pro/IS/Premier)
  • Which version…?
  • OS…? (32/64 Bit…? - which SP/Build…?)
  • Other security related software installed…?
  • Which AV(s) did you use before Avast…?