Issue
Atlassian Crowd and EasySSO do work together, but only if Atlassian Crowd is used as a user directory in the backend.
If (before you discovered the magic of EasySSO!) Atlassian Crowd was used for single sign-on then the Atlassian Crowd SSO configuration MAY interfere with EasySSO.
Solution
Integration with Atlassian Crowd for single sign-on is done in seraph-config.xml.
If you have integrated your Confluence with Atlassian Crowd you will need to remove Atlassian Crowd SSO authenticator from your Seraph-config.xml.