Solution : https://service.sap.com/sap/support/notes/1627773 (SAP Service marketplace login required)
Key words : 
run-time error r6025, symptom mdm import server, - change list # 99702- mdm 7, - change list # 98809- mdm 7, pure virtual call, - change list # 98869o, specific flaw addressed, specific platform/dbms, import server, error message
Related Notes : 
       
| 1656884 | SAP Release Note for MDM 7.1 SP06 Patch46 | 
| 1635783 | SAP Release Note for MDM 7.1 SP08 Patch01 | 
| 1626982 | SAP Release Note for MDM 7.1 SP07 Patch17 |