The specific menu is "Tools" and the menu item is "Manage Certificates". You then press "Add Exception" and re-input the URL. (This information is by no means intended to substitute for better documentation and better handling, I agree that there should be both.)
** Attachment added: "unnamed" http://launchpadlibrarian.net/12935443/unnamed -- clicking on an https link when the remote site has invalid credentials does not work https://bugs.launchpad.net/bugs/181893 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
