Solution : https://service.sap.com/sap/support/notes/397500 (SAP Service marketplace login required)
Key words : 
step add_on_conflict_checkthe system displays error message      ocs_get_objectlist, directory '/general/r3server/abap/note, delta task field refers, newer spam/saint versions, additional key words ehs, service computers sapservx, table entries exist, corrected object lists, transaction saint, field deltatask
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| 122400 | EH&S installation: Composite SAP Note |