The Directory Connector is configured correctly and the account settings are correct but when the connector was run it stopped immediately with the following error:
"ERROR CMN.logging  - Connector e2n-usersANDcontacts Id: 2944 exited with errors: 50: Insufficient access"
This is caused by the LDAP configuration settings in Domino not set to allow users to write back to the LDAP directory.
To resolve this issue, open the Domino Administrator client and locate the LDAP settings document in the Directory Settings section of the Configuration tab.
Depending on the environment, you may need to restart the Domino server.