Why do we see JBAS011006 Not installing optional component in JBoss EAP 6 when deplying a Spring application

Issue

• Getting this WARN and stacktrace in the log when deploying the application that bundles CXF:

11:08:40,879 INFO [org.jboss.as.osgi] (MSC service thread 1-1) JBAS011907: Register module: Module "deployment.test.war:main" from Service Module Loader
11:08:40,905 WARN [org.jboss.as.ee] (MSC service thread 1-6) JBAS011006: Not installing optional component org.apache.cxf.transport.http.Servlet3ContinuationProvider$Servlet3Continuation due to exception: org.jboss.as.server.deployment.DeploymentUnitProcessingException: JBAS011054: Could not find default constructor for class org.apache.cxf.transport.http.Servlet3ContinuationProvider$Servlet3Continuation
at org.jboss.as.ee.component.ComponentDescription$DefaultComponentConfigurator.configure(ComponentDescription.java:606) [jboss-as-ee-7.1.2.Final-redhat-1.jar:7.1.2.Final-redhat-1]
at org.jboss.as.ee.component.deployers.EEModuleConfigurationProcessor.deploy(EEModuleConfigurationProcessor.java:83) [jboss-as-ee-7.1.2.Final-redhat-1.jar:7.1.2.Final-redhat-1]
at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:116)
at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811)
at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [rt.jar:1.6.0_30]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [rt.jar:1.6.0_30]
at java.lang.Thread.run(Thread.java:662) [rt.jar:1.6.0_30]

• Getting the following logs when deploying application which packages Apache CXF:

16:49:46,419 WARN  [org.jboss.as.ee] (MSC service thread 1-4) JBAS011006: Composant optionnel org.apache.cxf.transport.http.Servlet3ContinuationProvider$Servlet3Continuation non installé à cause de l'exception: org.jboss.as.server.deployment.DeploymentUnitProcessingException: JBAS011054: Impossible de trouver le constructeur par défaut pour class org.apache.cxf.transport.http.Servlet3ContinuationProvider$Servlet3Continuation
..

• Getting the following logs when deploying application that bundles Metro Web Services:

16:48:57,302 WARN [org.jboss.as.ee] (MSC service thread 1-1) JBAS011006: Not installing optional component com.sun.xml.ws.transport.http.servlet.WSAsyncListener$1 due to exception: org.jboss.as.server.deployment.DeploymentUnitProcessingException: JBAS011054: Could not find default constructor for class com.sun.xml.ws.transport.http.servlet.WSAsyncListener$1
at org.jboss.as.ee.component.ComponentDescription$DefaultComponentConfigurator.configure(ComponentDescription.java:606) [jboss-as-ee-7.1.2.Final-redhat-1.jar:7.1.2.Final-redhat-1]
at org.jboss.as.ee.component.deployers.EEModuleConfigurationProcessor.deploy(EEModuleConfigurationProcessor.java:83) [jboss-as-ee-7.1.2.Final-redhat-1.jar:7.1.2.Final-redhat-1]
at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:116)
at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811)
at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [rt.jar:1.6.0_30]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [rt.jar:1.6.0_30]
at java.lang.Thread.run(Thread.java:662) [rt.jar:1.6.0_30]

Seeing this DEBUG message in EAP 6.4

12:12:12,123 DEBUG [org.jboss.as.ee] (MSC service thread 1-6) Not installing optional component org.springframework.web.context.request.async.StandardServletAsyncWebRequest due to an exception: org.jboss.as.server.deployment.DeploymentUnitProcessingException: WFLYEE0048: Could not find default constructor for class org.springframework.web.context.request.async.StandardServletAsyncWebRequest
    at org.jboss.as.ee.component.DefaultInterceptorConfigurator.configure(DefaultInterceptorConfigurator.java:92)
    at org.jboss.as.ee.component.deployers.EEModuleConfigurationProcessor.deploy(EEModuleConfigurationProcessor.java:82)
    at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:147)
    at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1948)
    at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1881)
    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:748)