ORA-39126 is a generic "Worker unexpected fatal error" that occurs during Oracle Data Pump operations. The specific sub-program KUPW$WORKER.PREPARE_DATA_IMP [71] typically points to an internal failure while the worker is preparing to import data rows into a table. Primary Causes & Solutions
If none of the above resolves the issue, please provide: ORA-39126 is a generic "Worker unexpected fatal error"
Run impdp with the INCLUDE=TABLE_DATA parameter to isolate data loading, and capture full error: ORA-39126 is a generic "Worker unexpected fatal error"
You will likely see an underlying ORA-XXXXX. Common examples: ORA-39126 is a generic "Worker unexpected fatal error"
Processing object type SCHEMA_EXPORT/TABLE/TABLE_DATA...
impdp ... table_exists_action=truncate
Sometimes reducing or increasing PARALLEL helps:
Increase PGA_AGGREGATE_TARGET dynamically: