SAP Message 01558 - Could not access the central system &1

Diagnosis
The action should have been executed on the central system &V1& of theCentral User Administration.
CASE &V2& .
WHEN '1' .
Could not access the system.
WHEN '2' .
Could not read the data, since the functionality required to do so doesnot exist in the central system.
ENDCASE

System Response
IF &V2& = 1 OR &V2& = 2 .
The required data was read locally.
In the following circumstances, this local data can be inconsistent inrelation to the actual landscape information in the central system:
Use of the selective save function in transaction SCUA
While changing the CUA landscape (adding or removing child systems),there was no RFC connection to a child system. You now want to read thelandscape information on this child system.
ENDIF

Procedure for System Administration
CASE &V2& .
WHEN '1' .
An RFC to the central system failed. Check the RFC destination that wasset up for central user maintenance, and which points to the centralsystem.
IF &V3& <> ' '.
Additional Information:
&V3&&V4&
ENDIF.
WHEN '2' .
Function module 'SUSR_ZBV_LANDSCAPE_GET' does not exist on the centralsystem of the CUA landscape.
Import the correction instructions from SAP Note 994415 into the centralsystem.
ENDCASE