UME Log on error during reference user resolution for SAP Biller Direct

Hi All,

I use UME LDAP user model;

• LDAP datasource in UME(ads_deep_readonly)
• UME user management setting in XCM

Web user, ABA000, is maintained in AD LDAP server and well replicated into UME engine

Reference user, BD_REF, was already created with SAP_FI_FSCM_ALL authorization in ECC and also mapped for web user in UMEADMIN (at 'fscm_refuser' field)

However, current log-on error for BD web user, ABA000, showed error;

=> general problem has occured within the logon. The error message is: {0}.

NWA>defulat trace showed that it failed to identify reference user information for web user at UME profile(even though already maintained in UMEADMIN),  and at a next step try to search web user in ECC

• "BAPI_USER_GET_DETAIL:SAP Backend Error(01124) User ABC000 does  not exist at com.sap.fin.webbase.um.FIUserManager.getReferenceUser (FIUserManager.java:112)"
  

Please share your idea and experience.

Best regard,
Ted