When you try to set the catalog as default, you have got this exception : (empty catalog or duplicate catalog have the same behaviour)
Stack trace of where session-ametys-18624 was originally closed java.lang.Exception: Stack trace of where session-ametys-18624 was originally closed at org.apache.jackrabbit.core.session.SessionState.close(SessionState.java:275) at org.apache.jackrabbit.core.SessionImpl.logout(SessionImpl.java:983) at org.apache.jackrabbit.core.XASessionImpl.logout(XASessionImpl.java:394) at org.ametys.plugins.repository.provider.AmetysSession.forceLogout(AmetysSession.java:85) at org.ametys.plugins.repository.dispatcher.JCRSessionDispatchRequestProcess.postProcess(JCRSessionDispatchRequestProcess.java:48) at org.ametys.core.ui.dispatcher.DispatchGenerator._dispatching(DispatchGenerator.java:230) at org.ametys.core.ui.dispatcher.DispatchGenerator.generate(DispatchGenerator.java:94)