因为数据库内部错误,数据字典不一致等原因导致 DataPump不能被正常使用,这个时候可以尝试着通过重建 DataPump来解决问题
sysdba登录数据库

SQL> connect / as sysdba

For Oracle version 10.1

1. Catdp.sql orders the installation of all its components including
   the Metadata API which was previously installed separately.
   By default catproc.sql invoke this script.
SQL >@ $ORACLE_HOME/rdbms/admin/catdp.sql
2. dbmspump.sql will create DBMS procedures for dataPUMP
SQL >@ $ORACLE_HOME/rdbms/admin/dbmspump.sql

For Oracle version 10.2

1. Catdph.sql will Re-Install DataPump types and views
SQL >@ $ORACLE_HOME/rdbms/admin/catdph.sql
Use this code to verify if XDB is installed:
SQL> select substr(comp_name,1,30) comp_name, substr(comp_id,1,10)
     comp_id,substr(version,1,12) version,status
     from dba_registry where comp_id='XDB';
Sample output if XDB installed,
Oracle XML Database            XDB        -version-   VALID
Note: If XDB is installed, then it is required to run "catmetx.sql" script also.
SQL> @ $ORACLE_HOME/rdbms/admin/catmetx.sql
2. prvtdtde.plb will Re-Install tde_library packages
SQL >@ $ORACLE_HOME/rdbms/admin/prvtdtde.plb
3. Catdpb.sql will Re-Install DataPump packages
SQL >@ $ORACLE_HOME/rdbms/admin/catdpb.sql
4.Dbmspump.sql will Re-Install DBMS DataPump objects
SQL >@ $ORACLE_HOME/rdbms/admin/dbmspump.sql
5. To recompile  invalid objects, if any
SQL >@ $ORACLE_HOME/rdbms/admin/utlrp.sql

For Oracle version 11g

1. Catproc.sql
SQL >@ $ORACLE_HOME/rdbms/admin/catproc.sql
2. To recompile invalid objects, if any
SQL >@ $ORACLE_HOME/rdbms/admin/utlrp.sql

参考:How To Reload Datapump Utility EXPDP/IMPDP [ID 430221.1]