Solution : https://service.sap.com/sap/support/notes/1010126 (SAP Service marketplace login required)
Key words :
prerequisites nw04 session management expects session termination event, terms ess business package, backend xss sytem remains, back-end system ecc 5, nw04 based iviews, back end system, internally solution check, customer upgrades portal, nw04 backend, nw04s portal