Solution : https://service.sap.com/sap/support/notes/679860 (SAP Service marketplace login required)
Key words : 
runtime error              objects_objref_not_assignedexception                  cx_sy_ref_is_initialin program saplrzx0, older support package versions, 0b            import support package 18, 1c            import support package 12, system error occurs, terms rsoadmin reason, 0b support package 18, 1 content support package 12, current support package, bw support packages
Related Notes : 
       
| 647747 | SAPBWNews BW 3.0B Support Package 18 | 
| 601038 | SAPBWNews BW 3.1 Content Support Package 12 | 
| 540873 |