ORA-31456: error executing a procedure in the DBMS_CDC_UTILITY package
Cause: An internal attempt to invoke a procedure within the DBMS_CDC_UTILITY package failed
Action: Check the trace logs for more information. Ensure that the package has been installed successfully. Try issuing a DESCRIBE command from SQL on the package. If it fails, then try reinstalling the package. If it succeeds then try invoking one of the procedures from SQL
https://support.oracle.com/
http://www.oracle.com/