[NetScaler] Error "KB Questions and Asnwers not registered" with LDAP KBAttribute

In a SSPR nFactor configuration. You may observe error "KB Questions and Asnwers not registered" when login with LDAP password and can't move to the next AAA factor. Triggers are: The LDAP factor has noschema boundInherits username & password from a previous factor. LDAP action has KBAttribute...