ORA-01306: dbms_logmnr.start_logmnr() must be invoked before selecting from v$logmnr_contents
Cause: A select was issued from v$logmnr_contents without first invoking the dbms_logmnr.start_logmnr() procedure.
Action: Invoke the dbms_logmnr.start_logmnr() procedure before issuing a select from the v$logmnr_contents view.