Firefox - Untrusted Site Certificate
Let's say you install Webmin and attempt to connect to it. With Firefox, you will see the following error in a pop-up box with only OK as an option.
localhost:10000 uses an invalid security certificate. The certificate is not trusted because the issuer certificate is not trusted. The certificate is not valid for any server names. (Error code: sec_error_untrusted_issuer)
Since webmin is only using the certificate for link encryption, you would like to bypass this test, but no options are presented. You must insert this exception manually.
Options -> Advanced -> Encryption -> View Certificates -> Server -> Add Exception