View Larger Image How to Fix Firefox Pkix Error Key Pinning Failure Problem: Some websites with security certificates don’t open and show error like ” MOZILLA_PKIX_ERROR_KEY_PINNING_FAILURE”, in that case, you can fix it and able to browse by below fix. Solution : Open firefox and go to about:config in address bar search and change value of ” security.cert_pinning.enforcement_level ” 1 to 0 clear cache and cookies close and open firefox, Now you can browse the websites without any problem of MOZILLA_PKIX_ERROR_KEY_PINNING_FAILURE error. Images for your reference: By HelloMails|2018-10-01T14:26:57+00:00September 1st, 2018|browsers|3 Comments Share This Story, Choose Your Platform! FacebookTwitterPinterestVkEmail About the Author: HelloMails 3 Comments denis January 11, 2020 at 1:49 pm - Reply thank you! helped! Maciek1003pl January 26, 2020 at 8:05 am - Reply But what when I have a “2”, no “1” in this ? This is automatic, when I’m going to config. HelloMails May 18, 2020 at 8:36 pm - Reply you can edit manually to 0 Leave A Comment Cancel replyComment Δ This site uses Akismet to reduce spam. Learn how your comment data is processed.