Solution : https://service.sap.com/sap/support/notes/123889 (SAP Service marketplace login required)
Key words : 
~ftp/general/frontend/patches/rel40b/windows/win32/gnsmx_z, additional key words, windows window, session manager, window displayed, vertical expansion, window corresponds, program error, graphics interface, solution patch 7
Related Notes : 
       
| 122495 | Session Manager: You cannot start reports | 
| 109053 | Session Manager: submenus are not displayed | 
| 107062 | Session Manager: Terminates together with OS/400 | 
| 103931 | Are more than five system registers possible? | 
| 96885 | Downloading front end patches |