Getting error ORA-39127 during data pump export of schema which uses Oracle Text

Here is a section of the DP export log:
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Processing object type SCHEMA_EXPORT/TABLE/INDEX/FUNCTIONAL_AND_BITMAP/INDEX
ORA-39127: unexpected error from call to local_str := SYS.DBMS_EXPORT_EXTENSION.GET_DOMAIN_INDEX_METADATA('CS_TEXT_IDX',,'TEXTINDEXMETHODS','CTXSYS',10.02.00.03.00,newblock,0)
ORA-20000: Oracle Text error:
DRG-10502: index "INTERNAL_EXTENSION_WMUSCOE_DB"."CS_TEXT_IDX" does not exist
ORA-06512: at "SYS.DBMS_EXPORT_EXTENSION", line 267
ORA-06512: at line 1
ORA-06512: at "SYS.DBMS_METADATA", line 4770
Processing object type SCHEMA_EXPORT/TABLE/INDEX/DOMAIN_INDEX/INDEX


This is the DP export parfile used:
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userid='/ as sysdba'
directory=dpump
dumpfile=test_export_fix.dmp