收到error log，查了一下错误信息，报以下错误

DATA COLLECTED
===============
EXP-00008: ORACLE error 4068 encountered
ORA-04068: existing state of packages has been discarded
ORA-04063: package body "SYS.LT_EXPORT_PKG" has errors
ORA-06508: PL/SQL: could not find program unit being called
ORA-06512: at line 1
EXP-00083: The previous problem occurred when calling SYS.LT_EXPORT_PKG.schema_info_exp

原因：

WORKSPACE , XDB 这2个schemas有invalid objects。用oem看程序包可以看到失效的object。

解决方法：

Run $ORACLE_HOME/rdbms/admin/owminst.plb as SYS to allow the LT_EXPORT_PKG to be validated

执行后问题解决。