Causa de un error en un exp y como solucionar

Al momento de realizar un Exp tengo el siguiente mensaje, por favor podrían indicarme a que se debe y si el error puede ocasionar un respaldo no confiable, ¿cómo puedo solucionar?:
Connected to: Oracle Database 10g Enterprise Edition Release 10.1.0.2.0 - Production
With the Partitioning, OLAP and Data Mining options
Export done in WE8ISO8859P1 character set and AL16UTF16 NCHAR character set
server uses WE8MSWIN1252 character set (possible charset conversion)
About to export the entire database ...
. Exporting tablespace definitions
. Exporting profiles
. Exporting user definitions
. Exporting roles
. Exporting resource costs
. Exporting rollback segment definitions
. Exporting database links
. Exporting sequence numbers
. Exporting directory aliases
. Exporting context namespaces
. Exporting foreign function library names
. Exporting PUBLIC type synonyms
. Exporting private type synonyms
. Exporting object type definitions
. Exporting system procedural objects and actions
. Exporting pre-schema procedural objects and actions
. Exporting cluster definitions
. About to export SYSTEM's tables via Conventional Path ...
. . Exporting table DEF$_AQCALL 0 rows exported
EXP-00056: ORACLE error 904 encountered
ORA-00904: "SYS"."DBMS_EXPORT_EXTENSION"."FUNC_INDEX_DEFAULT": invalid identifier
. . Exporting table DEF$_AQERROR 0 rows exported
EXP-00091: Exporting questionable statistics.
. . Exporting table DEF$_CALLDEST 0 rows exported
EXP-00056: ORACLE error 904 encountered
ORA-00904: "SYS"."DBMS_EXPORT_EXTENSION"."FUNC_INDEX_DEFAULT": invalid identifier
. . Exporting table DEF$_DEFAULTDEST 0 rows exported
EXP-00056: ORACLE error 904 encountered
ORA-00904: "SYS"."DBMS_EXPORT_EXTENSION"."FUNC_INDEX_DEFAULT": invalid identifier
. . Exporting table DEF$_DESTINATION 0 rows exported