Worker Unexpected Fatal Error In Kupw-worker.prepare-data-imp 71: Ora-39126

The KUPW$WORKER process is the core engine of Oracle Data Pump, responsible for orchestrating the export and import of database objects. When the worker dies from an unhandled exception, Oracle raises this error. While the main job may continue, any objects being processed by the failed worker will be incomplete or skipped altogether. Pinpointing the root cause is critical, as the error itself is a generic symptom of a variety of underlying problems.

The "71" refers to a specific internal trace point in the Data Pump code. It almost always indicates in the dump file, object definition incompatibility , or a bug in the Data Pump client/database version. The KUPW$WORKER process is the core engine of

Internal Data Pump packages or objects may be in an inconsistent state. Stale Dictionary Statistics: Pinpointing the root cause is critical, as the

The worker process requires enough Program Global Area (PGA) to prepare data, especially for large rows, LOBs, or row batches. If PGA_AGGREGATE_TARGET is too low, the worker may abort. Internal Data Pump packages or objects may be

A user trying to import an 11gR2 Windows dump into 12cR2 Linux encountered the ORA-39126 error. The solution was to explicitly exclude the SYSMAN and SYSTEM schemas from the import, as those system-level objects created conflicts during the data preparation phase.