Oracle Message LPX-01012 - [XQST0012] Invalid XML schema

ERROR[XQST0012] Invalid XML schema
CAUSEIt is a static error if the set of definitions contained in all schemas imported by a Prolog do not satisfy the conditions for schema validity specified in Sections 3 and 5 of [XMLSchema] Part 1 i.e., each definition must be valid, complete, and unique
ACTIONNone