Oracle Message ORA-19232 - XQST0012 - imported schemas violate validity rules

ERRORXQST0012 - imported schemas violate validity rules
CAUSEThe imported schemas did not satisfy the conditions for schema validity specified in the XMLSchema specification.
ACTIONFix the imported schemas to satisfy the validity rules.In particular, the definitions must be valid, complete, and unique -- that is, the pool of definitions must not contain two or more schema components with the same name and target namespace.