Oracle Message EXP-00078 - Error exporting metadata for index string. Index creation will be skipped

ERRORError exporting metadata for index string. Index creation will be skipped
CAUSEDomain indexes export private metadata via anonymous PL/SQL blocks prior to the CREATE INDEX statement. Export does this by calling the ODCIIndexGetMetadata method on the implementation type associated with the index. A problem occurred inside this routine. Because the metadata is considered an integral part of the index, the CREATE INDEX statement was not written to the dump file.
ACTIONContact the developer of the indexs implementation type. If this is an Oracle-supplied index (perhaps via a data cartridge), contact Oracle Worldwide Support.