GW2014 R2 GMS 14.2.0 build 279 dsapp v239

My problem is similar to what is described in thread "Duplicate Entry ?" opened 03-Mar-2016. However....

Trying to Add User using LDAP (AD). I get the error:

Duplicate Entry. User already exists on this connector:
CN=fred,OU=Users,DC=bigbox,DC=org

dsapp Health Check reports:

================================================== ========
Checking Databases Integrity..
================================================== ========
Not found in mobility database:
CN=fred,OU=Users,DC=bigbox,DC=org

dsapp force-remove of fred doesn't resolve the issue.

Any thoughts?