I've just upgraded our ovirt engine server to ovirt 4.6 and it appears that LDAP logins no longer work. When I attempt to log in using an AD account the following errors are shown in the engine log. 2018-09-11 10:03:44,610-04 ERROR [org.ovirt.engine.core.sso.servlets.InteractiveAuthServlet] (default task-10) [] Internal Server Error: Cannot locate principal 'username@example.com' 2018-09-11 10:03:44,610-04 ERROR [org.ovirt.engine.core.sso.utils.SsoUtils] (default task-10) [] Cannot locate principal 'username@example.com' 2018-09-11 10:03:44,645-04 ERROR [org.ovirt.engine.core.aaa.servlet.SsoPostLoginServlet] (default task-10) [] server_error: Cannot locate principal 'username@example.com' I have not changed any LDAP settings and ldapsearch is able to find this object without any issues. Does anybody have any idea what would cause this?