Solution : https://service.sap.com/sap/support/notes/595686 (SAP Service marketplace login required)
Key words : 
symptom runtime error convt_overflow occurs, 0b            import support package 11, 1c            import support package 05, method if_rsr_cache_buffer~get_quota, 0b support package 11, 1c support package 05, bw support packages, program error, support package 08, support package 02
Related Notes : 
       
| 571744 | SAPBWNews BW 3.1 Content Support Package 10 | 
| 571743 | SAPBWNews BW 3.1 Content Support Package 08 | 
| 571720 | SAPBWNews BW 3.1 Content Support Package 09 | 
| 539824 | SAPBWNews BW 3.1 Content Support Package 05 | 
| 523248 | SAPBWNews BW 3.0B Support Package 11 |