Solution : https://service.sap.com/sap/support/notes/496989 (SAP Service marketplace login required)
Key words : 
bw front-end patch includes procedure downloading bw front-end patches, /swcenter-mainthe sap download area appears, bw front-end check tool sapbexc, 0a/binary patches/sap gui windows, 0b front end requires sap gui 6, installing bw front-end patches distributing, \program files\common files\sap\system, sap business explorer web application designer, downloading bw front-end patches, saving web chart items destroyed
Related Notes : 
       
| 742553 | Installing BW 3.xX front-end patches | 
| 653950 | BW 3.xX Front-End Patch 11 | 
| 558914 | BW 3.1C: Dates for front-end patches | 
| 533990 | BEx Analyzer: Unable to execute query in customer namespace | 
| 526438 | Internal error with communication with the IGS | 
| 513977 | SAP GUI 6.20 Final Compilation 2 with BW 3.0B front end | 
| 511522 | Corrections to the front-end installation program | 
| 417397 | BW Frontend (Analyzer or sapbexc.xla) does not run | 
| 396452 | Server-based BW Frontend check | 
| 206609 | Compilation error in Excel (clBEXeventBuilder) | 
| 197460 | BW Frontend Checktool sapbexc.xla | 
| 142705 | Files for the BW support | 
| 96885 | Downloading front end patches | 
| 66971 | Supported SAP GUI platforms |