i`m having some troubles with kapersky and Firefox connection, i was using normally and i closed Firefox, 5 minutes later i tried to access Facebook and for my surprise i got "Your connection is not secure Error code: SEC_ERROR_UNKNOWN_ISSUER ". So i start searching solutions for this problem and the only one that works for me is options>additional>Network> In the Encrypted connections scanning section check the Do not scan encrypted connections option and confirm this change.