If there is an entity reference in schema that includes schema fragments, schema components defined in the included fragments do not get recognized. It appears that schema traversal does not take into account entity references. If I add a line: fSchemaGrammarParser.setFeature("http://apache.org/xml/features/dom/create- entity-ref-nodes", false); in XMLValidator.java It starts recognizing included schema components. -Takuki Kamiya