In the 12c databases, ORA-39014 ORA-39029 ORA-31671 and ORA-00600 errors can be received during expdp or impdp operation.
In such a case, existing processes are terminated and errors similar to the following will appear in the alert log file.
“DW00 terminating with fatal err=600”
The possible errors in export and import are as follows.
ORA-39014: One or more workers have prematurely exited.
ORA-39029: worker 1 with process name "DW00" prematurely terminated
ORA-31671: Worker process DW00 had an unhandled exception.
ORA-00600: internal error code, arguments: , [0x7FAD49A1E198], , , , , , , , , , 
To solve the problem, the value of the open_cursors parameter should be increased and the value of the parameter “_optimizer_cost_based_transformation” should be set to off.
SQL> alter system set open_cursors=1024 scope=both sid='*';
SQL> alter system set "_optimizer_cost_based_transformation"=off scope=both sid='*';
After the parameter change, the operations will be completed successfully.