Solution : https://service.sap.com/sap/support/notes/1530700 (SAP Service marketplace login required)
Key words :
html specific symptoms close button, sap netweaver businessclient, prerequisites program error, attached correction instructions, relevant support package, dynamic parameter 'system', correct sort order, close button, html version, sort order
Related Notes :
| 1507477 | 'Close' button for window in NWBC is not displayed |
| 1353538 | NWBC -Patch Collection- SERVER SIDE (ABAP)+NWBC for HTML |