Error:
Improper use? Potential bug? Your feedback is welcome:
Contact: basex-talk@mailman.uni-konstanz.de
Version: BaseX 8.6 beta baadd29
Java: Oracle Corporation, 1.8.0_112
OS: Linux, amd64
Stack Trace: 
java.lang.ArrayIndexOutOfBoundsException: 27
	at org.apache.xerces.impl.xs.XSConstraints.overlapUPA(Unknown Source)
	at org.apache.xerces.impl.xs.XSConstraints.overlapUPA(Unknown Source)
	at org.apache.xerces.impl.xs.models.XSDFACM.checkUniqueParticleAttribution(Unknown Source)
	at org.apache.xerces.impl.xs.XSConstraints.fullSchemaChecking(Unknown Source)
	at org.apache.xerces.impl.xs.XMLSchemaValidator.handleEndElement(Unknown Source)
	at org.apache.xerces.impl.xs.XMLSchemaValidator.endElement(Unknown Source)
	at org.apache.xerces.impl.XMLNSDocumentScannerImpl.scanEndElement(Unknown Source)
	at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
	at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
	at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
	at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
	at org.apache.xerces.jaxp.validation.StreamValidatorHelper.validate(Unknown Source)
	at org.apache.xerces.jaxp.validation.ValidatorImpl.validate(Unknown Source)
	at javax.xml.validation.Validator.validate(Validator.java:124)
	at org.basex.query.func.validate.ValidateXsd$1.process(ValidateXsd.java:97)
	at org.basex.query.func.validate.ValidateFn.process(ValidateFn.java:120)
	at org.basex.query.func.validate.ValidateXsd.errors(ValidateXsd.java:55)
	at org.basex.query.func.validate.ValidateFn.report(ValidateFn.java:88)
	at org.basex.query.func.validate.ValidateXsdReport.value(ValidateXsdReport.java:15)
	at org.basex.query.func.validate.ValidateFn.iter(ValidateFn.java:53)
	at org.basex.query.scope.MainModule.iter(MainModule.java:118)
	at org.basex.query.QueryContext.iter(QueryContext.java:331)
	at org.basex.query.QueryContext.cache(QueryContext.java:622)
	at org.basex.query.QueryProcessor.cache(QueryProcessor.java:116)
	at org.basex.core.cmd.AQuery.query(AQuery.java:87)
	at org.basex.core.cmd.XQuery.run(XQuery.java:22)
	at org.basex.core.Command.run(Command.java:255)
	at org.basex.core.Command.execute(Command.java:93)
	at org.basex.gui.GUI.exec(GUI.java:479)
	at org.basex.gui.GUI.access$3(GUI.java:433)
	at org.basex.gui.GUI$7.run(GUI.java:421)
Query:
validate:xsd-report(root())
Query plan:
<QueryPlan compiled="true">
  <ValidateXsdReport name="xsd-report(input[,schema[,version]])">
    <FnRoot name="root([node])"/>
  </ValidateXsdReport>
</QueryPlan>