I noticed this bug too. In my case it was Shibboleth. They may have to work with Shibboleth to integrate their services, because right now their website mentions support only for Suse and CentOS distros.
Temporarily your workaround can be edit /etc/hosts to add your ISP's static IP and domain address. This worked for me. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1866974 Title: The Diffie-Hellman prime sent by the server is not acceptable To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/evolution/+bug/1866974/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs