Oracle Database Error Code ORA-30446 Description :
valid workload queries not found
Error Cause:
None of the specified queries can be successfully parsed. The error may come from many sources: SQL syntax error, the owner specified by the load_workload subprograms do not match the real user who generates the SQL statement

How to Solve :
Only load valid SQL statements into the advisor repository. Make sure the statements can be parsed with privilege of the owner as specified in the owner parameter of the load_workload() subprogram.