Solution : https://service.sap.com/sap/support/notes/208591 (SAP Service marketplace login required)
Key words : 
//sapserv3/general/frontend/patches/rel46d/windows/win32use patch gui46d_255, latest frontend patch, additional key words calendar, windows dialog box, ocx solution import, alv grid control, 'cntl_error' exception occurs, calendar control, 'cntl_error' exception, additional information
Related Notes : 
       
| 326664 | |
| 322878 | |
| 147519 | Maintenance strategy / deadlines for SAP GUI | 
| 96885 | Downloading front end patches |