Solution : https://service.sap.com/sap/support/notes/387323 (SAP Service marketplace login required)
Key words : 
additional key words olap, unauthorized characters solution bw2, 0b            import support package 14, 1c            import support package 06, function group rrsi, function module rskc_allowed_char_get, business information warehouse, 0b support package 14, additionally allowed characters, incorrect data online
Related Notes : 
       
| 382565 | SAPBWNews BW 2.1C Support Package 06 | 
| 374840 | SAPBWNews BW 2.0B Support Package 14 |