Solution : https://service.sap.com/sap/support/notes/963992 (SAP Service marketplace login required)
Key words : 
rfc2 etq161 conflict check failed, sap erp central component 6, 4 etq233 calling function module, sap_hr support package sapke60001, sap_appl 600 support package 01, support package mentioned, sap_appl support package 04, log file occurs, limu comm objects, request/task sapkxxxxxx
Related Notes : 
       
| 913971 | Add. info. on upgrading to SAP ERP Central Component 6.0 SR1 |