Solution : https://service.sap.com/sap/support/notes/747089 (SAP Service marketplace login required)
Key words : 
symptom dynamic menus, terms subscreen reason, dynamic menu button, menu items, toolbar buttons, modal dialogs, main screen, modal dialog, 620 patch level 12, newer patch
Related Notes : 
       
| 563161 | SAP GUI, SAP ITS & SAP IGS patches on Service Marketplace | 
| 335521 | ITS patch installation of kernel files | 
| 330793 | Downloading patches |