Sorry to hear about this problem. Firefox has a couple different security error pages, and there are corresponding help articles for each one: * "Secure Connection Failed" -- typically has scantier information about the problem and if the padlock appears normally, can be taken to mean "connection failed" ** [[Troubleshoot the "Secure Connection Failed" error message]] This one describes how to remove Kaspersky's filtering as a possible factor: * [[How to troubleshoot "Your connection is not secure" error codes on secure websites]] Any improvement?