Solution : https://service.sap.com/sap/support/notes/681237 (SAP Service marketplace login required)
Key words :
older support package versions, 0b import support package 18, 1c import support package 12, rsdu_chkrep_all_psa_db6 function module, 0b support package 18, 1 content support package 12, current support package, bw support packages, existing psa tables, support package
Related Notes :
683651 | DB6: Table conversion doesn't process all PSA/ODS tables |
647747 | SAPBWNews BW 3.0B Support Package 18 |
601038 | SAPBWNews BW 3.1 Content Support Package 12 |