sun.security.validator.ValidatorException: No trusted certificate found (Setting up RM to connect to chiliproject)

I am trying to set up RM to connect to a Chiliproject server.

Chiliproject is a fork of Redmine so I figured I could try settings that are similar to those that I use when connecting to a Redmine server.

However, when I click the test button after adding a server I get the following error message:

sun.security.validator.ValidatorException: No trusted certificate found


Does this mean that the server did not present a certificate, or that I need to add the servers certificate somewhere on my system? If I need to add it locally, then please let me know where and how.

I am using Ubuntu Linux 11.10.