Solution : https://service.sap.com/sap/support/notes/427133 (SAP Service marketplace login required)
Key words :
rs_function_check_name function module issues, message 'function module, terms function builder, partner namespaces reason, partner namespace, sap namespace', customer system, sap_cus <> 'sap', solution import, service pack
Related Notes :
454354 | Change document: Function module name is in SAP namespace |