Solution : https://service.sap.com/sap/support/notes/1584882 (SAP Service marketplace login required)
Key words :
plugin webgui ~noheaderokcode ~webgui_simple_toolbar reason, activate standard simpl toolbar64, activate main menu button256, oldstyle template-based rendering, style rendering technology, ehp5 automatically switches, parameter ~noheaderokcode, note 1010519 ~webgui_simple_toolbar, longer supported, render mode
Related Notes :
| 1010519 | SAP GUI for HTML: Simplified title area w/o menu and OK code |