Hi am getting the follow error when trying to go to Tumblr sub-domains i.e. https://roeyourboat-.tumblr.com/: '''Did Not Connect: Potential Security Issue Firefox detected a potential security threat and did not continue to roeyourboat-.tumblr.com because this website requires a secure connection. What can you do about it? roeyourboat-.tumblr.com has a security policy called HTTP Strict Transport Security (HSTS), which means that Firefox can only connect to it securely. You can’t add an exception to visit this site. The issue is most likely with the website, and there is nothing you can do to resolve it. You can notify the website’s administrator about the problem. Learn more… Websites prove their identity via certificates. Firefox does not trust this site because it uses a certificate that is not valid for roeyourboat-.tumblr.com. The certificate is only valid for the following names: *.tumblr.com, tumblr.com Error code: SSL_ERROR_BAD_CERT_DOMAIN View Certificate''' This Certificate looks like this: '''https://roeyourboat-.tumblr.com/ Unable to communicate securely with peer: requested domain name does not match the server’s certificate. HTTP Strict Transport Security: true HTTP Public Key Pinning: false Certificate chain: -----BEGIN CERTIFICATE----- MIIGpzCCBY+gAwIBAgIRAOsw1/2DvyzYHRF0zq8c9xQwDQYJKoZIhvcNAQELBQAw gY8xCzAJBgNVBAYTAkdCMRswGQYDVQQIExJHcmVhdGVyIE1hbmNoZXN0ZXIxEDAO BgNVBAcTB1NhbGZvcmQxGDAWBgNVBAoTD1NlY3RpZ28gTGltaXRlZDE3MDUGA1UE AxMuU2VjdGlnbyBSU0EgRG9tYWluIFZhbGlkYXRpb24gU2VjdXJlIFNlcnZlciBD QTAeFw0yMDAzMjYwMDAwMDBaFw0yMjA2MjgwMDAwMDBaMBcxFTATBgNVBAMMDCou dHVtYmxyLmNvbTCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAPe+MXhf 4lZYnrsY5Ch1L0MqHOc44hIHkmawVVyTA8CynfbbFJWW+3Uoy0tHTcRgXyaV9xU3 oFyaIyYsLEUzfQLLmCuUjs8zSYvDH0jioCAz2HnkBaSuRAeOL2Iuaa9RoUVPrm8H TwMwNQEjTJXM9SdSDzK8fS78jglTpzy+1CvWXjo9ij4+hiz2UjRkntA1oKXtOgnm 7W63CwD+fs9cW4VJaehjIAXf8AM/vd/WTrsDmr2ne17D05Lg7UgIJJaAo7JkF7bt v3Be/BEYQTo/Eo0Ao9mqbt0DotNRn3lyh1y6MMhU7Hbr/qQzq1+cyEr+d0yd/ugp P4c3HKfxD21+6PUCAwEAAaOCA3MwggNvMB8GA1UdIwQYMBaAFI2MXsRUrYrhd+mb +ZsF4bgBjWHhMB0GA1UdDgQWBBR7eUPnbT0TNZdZJ9sYGcIV+LV+zzAOBgNVHQ8B 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I cannot find away of bypassing this in Firefox. Some Tumblr sub-domains work while others don't. I believe the answer to this is that the url contains a dash at the end of the sub-domain those that work properly do not contain the dash.