Solution : https://service.sap.com/sap/support/notes/209448 (SAP Service marketplace login required)
Key words : 
\program files\sappc\sapgui\themes\bw\<sid>, \program files\sappc\sapgui\themes\default, \program files\sappc\bw\wdbbapp, hkey_local_machine\software\sap\bex\browser\<sid>, gui\windows\win32\bw\themes, classname    bw_catalogclasstype    boobjkey       sap_bw_bitmap_ checking, /mimes/webrfc/bw/bexbrowser/cluster, system receive identical folder symbols, sap enjoy color palette, 0a backend support package 8
Related Notes : 
       
| 517950 | SAPBWNews BW 3.0B Support Package 07 | 
| 377680 | Accessing directory /sapgui/themes/bw/... | 
| 318352 | BEx browser in the Web |