Hi,
Please check j2ee_admin in client 001 of you have not changed the client. Please check that j2ee_admin is not locked .
Try to open config tools and see if it asks you any error.
User the below link for confitool.
http://help.sap.com/saphelp_nw04/helpdata/en/ae/b7ceff3e40fd42be3a6503236f9746/content.htm
Please also check that you have not used j2ee_admin in System Administration --> System Configuration --> UME Configuration.
If yes then you will have to change j2ee_admin in configtool for the ume configuration.
Thanks
Rishi Abrol