Solution : https://service.sap.com/sap/support/notes/1023893 (SAP Service marketplace login required)
Key words :
url parameter sap-syscmd=nocookie, waive session cookies completely, bex web-based application, relevant support package, web query reason, terms session handling, session cookies overwrite, web interface builder, session cookies, parameter = web_sessioncookie
Related Notes :
1613851 | BPS_STS_START:Session timeout after status history is called |
1132985 | Follow-on note for Note 1023893 - no sessioncookie |