I have a user federation connected to Active Directory that works for authenticating users but I'm trying to create / modify LDAP users and it appears that I'm getting the error ENTRY_EXISTS because it's not filling the CN= attribute: Caused by: javax.naming.NameAlreadyBoundException: [LDAP: error code 68 - 00002071: UpdErr: DSID-0305038D, problem 6005 (ENTRY_EXISTS), data 0 In an attempt to get this working I've made the following changes to the federation: Changed Sync Registrations to ON Ensured RDN LDAP attribute set to cn Created a mapper called "fullname"; Mapper Type: "Full Name"; category "Attribute Mapper"; Type "Full Name"; LDAP Full Name Attribute: cn; read only OFF; write only: OFF Can anybody help me with what I missed? *** This communication has been sent from World Fuel Services Corporation or its subsidiaries or its affiliates for the intended recipient only and may contain proprietary, confidential or privileged information. If you are not the intended recipient, any review, disclosure, copying, use, or distribution of the information included in this communication and any attachments is strictly prohibited. If you have received this communication in error, please notify us immediately by replying to this communication and delete the communication, including any attachments, from your computer. Electronic communications sent to or from World Fuel Services Corporation or its subsidiaries or its affiliates may be monitored for quality assurance and compliance purposes.***