I have this from the debugger hanging:
"MSC service thread 1-8@2725" prio=5 tid=0x1a nid=NA runnable
  java.lang.Thread.State: RUNNABLE
	  at java.net.SocketInputStream.socketRead0(SocketInputStream.java:-1)
	  at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
	  at java.net.SocketInputStream.read(SocketInputStream.java:170)
	  at java.net.SocketInputStream.read(SocketInputStream.java:141)
	  at org.apache.http.impl.io.SessionInputBufferImpl.streamRead(SessionInputBufferImpl.java:139)
	  at org.apache.http.impl.io.SessionInputBufferImpl.fillBuffer(SessionInputBufferImpl.java:155)
	  at org.apache.http.impl.io.SessionInputBufferImpl.readLine(SessionInputBufferImpl.java:284)
	  at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:140)
	  at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:57)
	  at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:261)
	  at org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:165)
	  at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:272)
	  at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:124)
	  at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:271)
	  at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:184)
	  at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:88)
	  at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
	  at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184)
	  at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
	  at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:55)
	  at org.jboss.resteasy.client.jaxrs.engines.ApacheHttpClient4Engine.invoke(ApacheHttpClient4Engine.java:285)
	  at org.jboss.resteasy.client.jaxrs.internal.ClientInvocation.invoke(ClientInvocation.java:454)
	  at org.jboss.resteasy.client.jaxrs.internal.ClientInvocationBuilder.put(ClientInvocationBuilder.java:175)
	  at org.jboss.narayana.rest.integration.RecoveryManager.synchronizeParticipantUrlWithCoordinator(RecoveryManager.java:244)
	  at org.jboss.narayana.rest.integration.RecoveryManager.recreateParticipantInformation(RecoveryManager.java:202)
	  at org.jboss.narayana.rest.integration.RecoveryManager.recoverParticipants(RecoveryManager.java:153)
	  at org.jboss.narayana.rest.integration.RecoveryManager.registerDeserializer(RecoveryManager.java:62)
	  at org.jboss.narayana.rest.integration.ParticipantsManagerImpl.registerDeserializer(ParticipantsManagerImpl.java:105)
	  at org.jboss.narayana.rest.bridge.inbound.InboundBridgeManager.<init>(InboundBridgeManager.java:60)
	  at org.jboss.narayana.rest.bridge.inbound.InboundBridgeManager.getInstance(InboundBridgeManager.java:50)
	  - locked <0x2aba> (a java.lang.Class)
	  at org.wildfly.extension.rts.service.InboundBridgeService.start(InboundBridgeService.java:53)
	  at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1963)
	  at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1896)
	  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)