NPE in HttpResponseConduit

I got this problem:
2016-01-10 11:19:06,026 INFO [cn.org.gddsn.sss.server.SSSSessionListener] (default task-65) Session Id YlASoaRZigqIVzOUMQB_nxeMl1eluerHurcbRG-u created.
2016-01-10 11:19:06,029 INFO [cn.org.gddsn.sss.server.SSSResourceImpl] (default task-65) User jeew(127.0.0.1:57300) login in session YlASoaRZigqIVzOUMQB_nxeMl1eluerHurcbRG-u.
2016-01-10 11:19:06,046 INFO [cn.org.gddsn.sss.server.MiniSeedSender] (default task-66) Send Mini Seed Queue size: 64
2016-01-10 11:19:06,047 INFO [cn.org.gddsn.sss.server.MiniSeedSender] (default task-66) MiniSeedSender for jeew starting...
2016-01-10 11:21:20,989 INFO [cn.org.gddsn.sss.server.SSSSessionListener] (default task-96) Session Id lO2XhoMjwGlgDWXqGynGFX4WiP_b6OERlvFO-8wS created.
2016-01-10 11:21:28,909 ERROR [io.undertow.request] (default task-66) UT005023: Exception handling request to /jopens-sss/sss/retr;staList=%20GD%2FPA01;chanMask=0x7fffffff;sn=-1: org.jboss.resteasy.spi.UnhandledException: RESTEASY003770: Response is committed, can't handle exception
at org.jboss.resteasy.core.SynchronousDispatcher.writeException(SynchronousDispatcher.java:167)
at org.jboss.resteasy.core.SynchronousDispatcher.writeResponse(SynchronousDispatcher.java:471)
at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:415)
at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:202)
at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:221)
at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:56)
at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:51)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85)
at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131)
at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)
at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)
at io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50)
at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:284)
at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:263)
at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81)
at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:174)
at io.undertow.server.Connectors.executeRootHandler(Connectors.java:202)
at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:793)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
at io.undertow.server.protocol.http.HttpResponseConduit.write(HttpResponseConduit.java:638)
at io.undertow.conduits.ChunkedStreamSinkConduit.doWrite(ChunkedStreamSinkConduit.java:163)
at io.undertow.conduits.ChunkedStreamSinkConduit.write(ChunkedStreamSinkConduit.java:127)
at org.xnio.conduits.ConduitStreamSinkChannel.write(ConduitStreamSinkChannel.java:150)
at io.undertow.channels.DetachableStreamSinkChannel.write(DetachableStreamSinkChannel.java:240)
at io.undertow.server.HttpServerExchange$WriteDispatchChannel.write(HttpServerExchange.java:2000)
at io.undertow.servlet.spec.ServletOutputStreamImpl.writeBufferBlocking(ServletOutputStreamImpl.java:567)
at io.undertow.servlet.spec.ServletOutputStreamImpl.flushInternal(ServletOutputStreamImpl.java:482)
at io.undertow.servlet.spec.ServletOutputStreamImpl.flush(ServletOutputStreamImpl.java:469)
at org.jboss.resteasy.plugins.server.servlet.HttpServletResponseWrapper$DeferredOutputStream.flush(HttpServletResponseWrapper.java:52)
at org.jboss.resteasy.util.CommitHeaderOutputStream.flush(CommitHeaderOutputStream.java:78)
at cn.org.gddsn.sss.server.MiniSeedSender.run(MiniSeedSender.java:84)
at cn.org.gddsn.sss.server.SSSResourceImpl$1.write(SSSResourceImpl.java:182)
at org.jboss.resteasy.plugins.providers.StreamingOutputProvider.writeTo(StreamingOutputProvider.java:32)
at org.jboss.resteasy.plugins.providers.StreamingOutputProvider.writeTo(StreamingOutputProvider.java:17)
at org.jboss.resteasy.core.interception.AbstractWriterInterceptorContext.writeTo(AbstractWriterInterceptorContext.java:131)
at org.jboss.resteasy.core.interception.ServerWriterInterceptorContext.writeTo(ServerWriterInterceptorContext.java:60)
at org.jboss.resteasy.core.interception.AbstractWriterInterceptorContext.proceed(AbstractWriterInterceptorContext.java:120)
at org.jboss.resteasy.security.doseta.DigitalSigningInterceptor.aroundWriteTo(DigitalSigningInterceptor.java:145)
at org.jboss.resteasy.core.interception.AbstractWriterInterceptorContext.proceed(AbstractWriterInterceptorContext.java:124)
at org.jboss.resteasy.plugins.interceptors.encoding.GZIPEncodingInterceptor.aroundWriteTo(GZIPEncodingInterceptor.java:100)
at org.jboss.resteasy.core.interception.AbstractWriterInterceptorContext.proceed(AbstractWriterInterceptorContext.java:124)
at org.jboss.resteasy.core.ServerResponseWriter.writeNomapResponse(ServerResponseWriter.java:98)
at org.jboss.resteasy.core.SynchronousDispatcher.writeResponse(SynchronousDispatcher.java:466)
... 33 more

2016-01-10 11:21:28,912 ERROR [io.undertow.request] (default task-66) UT005071: Undertow request failed HttpServerExchange{ GET /jopens-sss/sss/retr;staList=%20GD%2FPA01;chanMask=0x7fffffff;sn=-1 request

{Accept=[text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2], Connection=[keep-alive], Cookie=[JSESSIONID=YlASoaRZigqIVzOUMQB_nxeMl1eluerHurcbRG-u.mbp], User-Agent=[Java/1.8.0_66], Host=[127.0.0.1:8080]}

response {Connection=[keep-alive], X-Powered-By=[Undertow/1], Server=[WildFly/10], Transfer-Encoding=[chunked], Content-Type=[application/octet-stream], Date=[Sun, 10 Jan 2016 03:19:15 GMT]}}: java.lang.NullPointerException
at io.undertow.server.protocol.http.HttpResponseConduit.truncateWrites(HttpResponseConduit.java:739)
at io.undertow.conduits.ChunkedStreamSinkConduit.terminateWrites(ChunkedStreamSinkConduit.java:302)
at org.xnio.conduits.ConduitStreamSinkChannel.shutdownWrites(ConduitStreamSinkChannel.java:178)
at io.undertow.channels.DetachableStreamSinkChannel.shutdownWrites(DetachableStreamSinkChannel.java:79)
at io.undertow.servlet.spec.ServletOutputStreamImpl.close(ServletOutputStreamImpl.java:608)
at io.undertow.servlet.spec.HttpServletResponseImpl.closeStreamAndWriter(HttpServletResponseImpl.java:476)
at io.undertow.servlet.spec.HttpServletResponseImpl.responseDone(HttpServletResponseImpl.java:560)
at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:331)
at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:263)
at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81)
at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:174)
at io.undertow.server.Connectors.executeRootHandler(Connectors.java:202)
at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:793)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

2016-01-10 11:21:28,920 ERROR [stderr] (default task-66) Exception in thread "default task-66" java.lang.NullPointerException
2016-01-10 11:21:28,921 ERROR [stderr] (default task-66) at io.undertow.server.protocol.http.HttpResponseConduit.write(HttpResponseConduit.java:605)
2016-01-10 11:21:28,921 ERROR [stderr] (default task-66) at io.undertow.conduits.ChunkedStreamSinkConduit.flush(ChunkedStreamSinkConduit.java:267)
2016-01-10 11:21:28,921 ERROR [stderr] (default task-66) at org.xnio.conduits.ConduitStreamSinkChannel.flush(ConduitStreamSinkChannel.java:162)
2016-01-10 11:21:28,921 ERROR [stderr] (default task-66) at io.undertow.channels.DetachableStreamSinkChannel.flush(DetachableStreamSinkChannel.java:119)
2016-01-10 11:21:28,922 ERROR [stderr] (default task-66) at io.undertow.server.HttpServerExchange.closeAndFlushResponse(HttpServerExchange.java:1652)
2016-01-10 11:21:28,922 ERROR [stderr] (default task-66) at io.undertow.server.HttpServerExchange.endExchange(HttpServerExchange.java:1630)
2016-01-10 11:21:28,922 ERROR [stderr] (default task-66) at io.undertow.server.Connectors.executeRootHandler(Connectors.java:226)
2016-01-10 11:21:28,922 ERROR [stderr] (default task-66) at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:793)
2016-01-10 11:21:28,923 ERROR [stderr] (default task-66) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
2016-01-10 11:21:28,923 ERROR [stderr] (default task-66) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
2016-01-10 11:21:28,923 ERROR [stderr] (default task-66) at java.lang.Thread.run(Thread.java:745)

Not seen in wildfly-9.0.2.