17:21:31,829 ERROR [io.undertow.request] (XNIO-1 task-8) Undertow request failed HttpServerExchange{ GET /management/subsystem/io/worker/default}: java.lang.IllegalArgumentException: value is null
	at org.jboss.dmr.ModelNode.<init>(ModelNode.java:162) [jboss-dmr-1.2.0.Final.jar:1.2.0.Final]
	at org.jboss.as.domain.http.server.Common.sendError(Common.java:62) [wildfly-domain-http-interface-9.0.0.Alpha1-SNAPSHOT.jar:9.0.0.Alpha1-SNAPSHOT]
	at org.jboss.as.domain.http.server.DomainApiHandler.handleRequest(DomainApiHandler.java:141) [wildfly-domain-http-interface-9.0.0.Alpha1-SNAPSHOT.jar:9.0.0.Alpha1-SNAPSHOT]
	at org.jboss.as.domain.http.server.security.SubjectDoAsHandler$1.run(SubjectDoAsHandler.java:72) [wildfly-domain-http-interface-9.0.0.Alpha1-SNAPSHOT.jar:9.0.0.Alpha1-SNAPSHOT]
	at org.jboss.as.domain.http.server.security.SubjectDoAsHandler$1.run(SubjectDoAsHandler.java:68) [wildfly-domain-http-interface-9.0.0.Alpha1-SNAPSHOT.jar:9.0.0.Alpha1-SNAPSHOT]
	at java.security.AccessController.doPrivileged(Native Method) [rt.jar:1.7.0_51]
	at javax.security.auth.Subject.doAs(Subject.java:415) [rt.jar:1.7.0_51]
	at org.jboss.as.controller.AccessAuditContext.doAs(AccessAuditContext.java:94) [wildfly-controller-9.0.0.Alpha1-SNAPSHOT.jar:9.0.0.Alpha1-SNAPSHOT]
	at org.jboss.as.domain.http.server.security.SubjectDoAsHandler.handleRequest(SubjectDoAsHandler.java:68) [wildfly-domain-http-interface-9.0.0.Alpha1-SNAPSHOT.jar:9.0.0.Alpha1-SNAPSHOT]
	at org.jboss.as.domain.http.server.security.SubjectDoAsHandler.handleRequest(SubjectDoAsHandler.java:63) [wildfly-domain-http-interface-9.0.0.Alpha1-SNAPSHOT.jar:9.0.0.Alpha1-SNAPSHOT]
	at io.undertow.server.handlers.BlockingHandler.handleRequest(BlockingHandler.java:50) [undertow-core-1.1.0.Beta1.jar:1.1.0.Beta1]
	at org.jboss.as.domain.http.server.DomainApiCheckHandler.handleRequest(DomainApiCheckHandler.java:83) [wildfly-domain-http-interface-9.0.0.Alpha1-SNAPSHOT.jar:9.0.0.Alpha1-SNAPSHOT]
	at io.undertow.security.handlers.AuthenticationCallHandler.handleRequest(AuthenticationCallHandler.java:52) [undertow-core-1.1.0.Beta1.jar:1.1.0.Beta1]
	at io.undertow.server.Connectors.executeRootHandler(Connectors.java:195) [undertow-core-1.1.0.Beta1.jar:1.1.0.Beta1]
	at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:733) [undertow-core-1.1.0.Beta1.jar:1.1.0.Beta1]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_51]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_51]
	at java.lang.Thread.run(Thread.java:744) [rt.jar:1.7.0_51]