Prevention is far more efficient than cure. To minimize the risk of ORA-39126:
If Data Pump continues to fail, export using legacy exp and import with imp (may lose advanced features but works for many data-only scenarios). Prevention is far more efficient than cure
Data Pump remains one of the most powerful tools in the Oracle DBA’s arsenal. With patience and the right diagnostic approach, even a "fatal error" becomes a solvable puzzle. Prevention is far more efficient than cure