Seeing ConcurrentModificationException occasionally when deploying RESTEasy application in JBoss EAP 6

Issue

• During server startup, while multiple artifacts are being deployed in parallel by the server, a ConcurrentModificationException occurs that prevents an artifact from being correctly deployed :

ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[default-host].[/test-app]] (ServerService Thread Pool -- 45) JBWEB000287: Exception sending context initialized event to listener instance of class org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap: java.lang.RuntimeException: java.lang.RuntimeException: RESTEASY001795: Unable to instantiate MessageBodyReader
  at org.jboss.resteasy.plugins.providers.RegisterBuiltin.register(RegisterBuiltin.java:32) [resteasy-jaxrs-2.3.12.Final-redhat-1.jar:]
  at org.jboss.resteasy.spi.ResteasyDeployment.start(ResteasyDeployment.java:219) [resteasy-jaxrs-2.3.12.Final-redhat-1.jar:]
  at org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap.contextInitialized(ResteasyBootstrap.java:28) [resteasy-jaxrs-2.3.12.Final-redhat-1.jar:]
  at org.apache.catalina.core.StandardContext.contextListenerStart(StandardContext.java:3339) [jbossweb-7.5.12.Final-redhat-1.jar:7.5.12.Final-redhat-1]
  at org.apache.catalina.core.StandardContext.start(StandardContext.java:3780) [jbossweb-7.5.12.Final-redhat-1.jar:7.5.12.Final-redhat-1]
  at org.jboss.as.web.deployment.WebDeploymentService.doStart(WebDeploymentService.java:163) [jboss-as-web-7.5.5.Final-redhat-3.jar:7.5.5.Final-redhat-3]
  at org.jboss.as.web.deployment.WebDeploymentService.access$000(WebDeploymentService.java:61) [jboss-as-web-7.5.5.Final-redhat-3.jar:7.5.5.Final-redhat-3]
  at org.jboss.as.web.deployment.WebDeploymentService$1.run(WebDeploymentService.java:96) [jboss-as-web-7.5.5.Final-redhat-3.jar:7.5.5.Final-redhat-3]
  at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [rt.jar:1.8.0_45]
  at java.util.concurrent.FutureTask.run(FutureTask.java:266) [rt.jar:1.8.0_45]
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [rt.jar:1.8.0_45]
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [rt.jar:1.8.0_45]
  at java.lang.Thread.run(Thread.java:745) [rt.jar:1.8.0_45]
  at org.jboss.threads.JBossThread.run(JBossThread.java:122)
Caused by: java.lang.RuntimeException: RESTEASY001795: Unable to instantiate MessageBodyReader
  at org.jboss.resteasy.spi.ResteasyProviderFactory.registerProvider(ResteasyProviderFactory.java:837) [resteasy-jaxrs-2.3.12.Final-redhat-1.jar:]
  at org.jboss.resteasy.plugins.providers.RegisterBuiltin.registerProviders(RegisterBuiltin.java:67) [resteasy-jaxrs-2.3.12.Final-redhat-1.jar:]
  at org.jboss.resteasy.plugins.providers.RegisterBuiltin.register(RegisterBuiltin.java:28) [resteasy-jaxrs-2.3.12.Final-redhat-1.jar:]
  ... 13 more
Caused by: java.util.ConcurrentModificationException
  at java.util.ArrayList.sort(ArrayList.java:1456) [rt.jar:1.8.0_45]
  at java.util.Collections.sort(Collections.java:141) [rt.jar:1.8.0_45]
  at org.jboss.resteasy.core.MediaTypeMap.add(MediaTypeMap.java:281) [resteasy-jaxrs-2.3.12.Final-redhat-1.jar:]
  at org.jboss.resteasy.spi.ResteasyProviderFactory.addMessageBodyReader(ResteasyProviderFactory.java:518) [resteasy-jaxrs-2.3.12.Final-redhat-1.jar:]
  at org.jboss.resteasy.spi.ResteasyProviderFactory.addMessageBodyReader(ResteasyProviderFactory.java:480) [resteasy-jaxrs-2.3.12.Final-redhat-1.jar:]
  at org.jboss.resteasy.spi.ResteasyProviderFactory.registerProvider(ResteasyProviderFactory.java:833) [resteasy-jaxrs-2.3.12.Final-redhat-1.jar:]
  ... 15 more