ORA-39097: Data Pump job encountered unexpected error -12801
ORA-39065: unexpected master process exception in MAIN
ORA-12801: error signaled in parallel query server P..., instance <instance_name>
ORA-01460: unimplemented or unreasonable conversion requested Job <job_name> stopped due to fatal error at <failure_time>.
The problem seems to be a bug and the solution can be an update to minimum 18.104.22.168 version.
For me, the workaround was:
> alter system set PARALLEL_FORCE_LOCAL=TRUE;