Before attempting to add a new attribute to an Active Directory Object, here are a few steps to help ensure success:
- Make sure that the attribute either already exists in the Active Directory forest or can schema-extend the forest, and verify that the attribute is correctly mapped to the class of the object
- Verify that the account you will be using to add the new attribute has the proper permissions
- Check the security settings of the object to ensure that you are allowed to set the new values of the new attribute
- Check any replication constraints to make sure that all relevant sites are updated with the new attribute
- Verify any applications that use the attribute to ensure that the new value you are setting is supported