Solution : https://service.sap.com/sap/support/notes/904155 (SAP Service marketplace login required)
Key words :
exit_url = app-exit_url namespace = app-appl_ns, thetext representing <img> html element content, = app-appl_name page = app-page_name, suddenly html source code appears, bsp application system -> page sessionexit, terms business server pages, system application page sessionexit, select page sessionexit, bsp application system, img width=quot