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 :

  1. Open firefox and go to about:config in address bar
  2. search and change value of ” security.cert_pinning.enforcement_level ” 1 to 0
  3. clear cache and cookies
  4. 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:

How to Fix Firefox Pkix Error Key Pinning Failure
Firefox Pkix Error Key Pinning Error