reference:
https://asktom.oracle.com/pls/apex/asktom.search?tag=getting-ora-31626-job-does-not-exist-and-ora-06512-from-my-export-data-pump-job
oracle ORA-31626: Job does not exist
SELECT o.status, o.object_id, o.object_type, o.owner||'.'||object_name
FROM dba_objects o, dba_datapump_jobs j
WHERE o.owner=j.owner_name
AND o.object_name=j.job_name;
Solution: drop those tables then restart DB.