As part of overall NETVIRT-719 see full log attached there, there are a number of problems like the following from Pax Web in the log of Karaf 4 (only) based distributions during its shutdown (after a Ctrl-D in its console):

2017-06-08 15:52:46,728 | ERROR | Framework stop | AbstractFilter | 131 - org.apache.shiro.web - 1.3.2 | Unable to start Filter: [No WebEnvironment found: no EnvironmentLoaderListener registered?].
java.lang.IllegalStateException: No WebEnvironment found: no EnvironmentLoaderListener registered?
at org.apache.shiro.web.util.WebUtils.getRequiredWebEnvironment(WebUtils.java:277)[131:org.apache.shiro.web:1.3.2]
at org.apache.shiro.web.servlet.ShiroFilter.init(ShiroFilter.java:73)[131:org.apache.shiro.web:1.3.2]
at org.opendaylight.aaa.shiro.filters.AAAShiroFilter.init(AAAShiroFilter.java:48)[178:org.opendaylight.aaa.shiro:0.6.0.SNAPSHOT]
at org.apache.shiro.web.servlet.AbstractShiroFilter.onFilterConfigSet(AbstractShiroFilter.java:152)[131:org.apache.shiro.web:1.3.2]
at org.apache.shiro.web.servlet.AbstractFilter.init(AbstractFilter.java:97)[131:org.apache.shiro.web:1.3.2]
at org.eclipse.jetty.servlet.FilterHolder.initialize(FilterHolder.java:138)[148:org.eclipse.jetty.servlet:9.2.19.v20160908]
at org.eclipse.jetty.servlet.ServletHandler.initialize(ServletHandler.java:852)[148:org.eclipse.jetty.servlet:9.2.19.v20160908]
at org.eclipse.jetty.servlet.ServletHandler.updateMappings(ServletHandler.java:1526)[148:org.eclipse.jetty.servlet:9.2.19.v20160908]
at org.eclipse.jetty.servlet.ServletHandler.setFilterMappings(ServletHandler.java:1560)[148:org.eclipse.jetty.servlet:9.2.19.v20160908]
at org.ops4j.pax.web.service.jetty.internal.JettyServerImpl$5.call(JettyServerImpl.java:597)[385:org.ops4j.pax.web.pax-web-jetty:4.3.0]
at org.ops4j.pax.web.service.jetty.internal.JettyServerImpl$5.call(JettyServerImpl.java:593)[385:org.ops4j.pax.web.pax-web-jetty:4.3.0]
at org.ops4j.pax.swissbox.core.ContextClassLoaderUtils.doWithClassLoader(ContextClassLoaderUtils.java:60)[385:org.ops4j.pax.web.pax-web-jetty:4.3.0]
at org.ops4j.pax.web.service.jetty.internal.JettyServerImpl.removeFilter(JettyServerImpl.java:592)[385:org.ops4j.pax.web.pax-web-jetty:4.3.0]
at org.ops4j.pax.web.service.jetty.internal.ServerControllerImpl$Started.removeFilter(ServerControllerImpl.java:320)[385:org.ops4j.pax.web.pax-web-jetty:4.3.0]
at org.ops4j.pax.web.service.jetty.internal.ServerControllerImpl.removeFilter(ServerControllerImpl.java:150)[385:org.ops4j.pax.web.pax-web-jetty:4.3.0]
at org.ops4j.pax.web.service.internal.HttpServiceStarted.unregisterFilter(HttpServiceStarted.java:604)[387:org.ops4j.pax.web.pax-web-runtime:4.3.0]
at org.ops4j.pax.web.service.internal.HttpServiceProxy.unregisterFilter(HttpServiceProxy.java:232)[387:org.ops4j.pax.web.pax-web-runtime:4.3.0]
at org.ops4j.pax.web.extender.war.internal.UnregisterWebAppVisitorWC.visit(UnregisterWebAppVisitorWC.java:171)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.model.WebApp.accept(WebApp.java:666)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.WebAppPublisher$WebAppDependencyListener.unregister(WebAppPublisher.java:266)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.WebAppPublisher$WebAppDependencyListener.removedService(WebAppPublisher.java:224)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.WebAppPublisher$WebAppDependencyListener.removedService(WebAppPublisher.java:135)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.osgi.util.tracker.ServiceTracker$Tracked.customizerRemoved(ServiceTracker.java:967)[org.osgi.core-6.0.0.jar:]
at org.osgi.util.tracker.ServiceTracker$Tracked.customizerRemoved(ServiceTracker.java:870)[org.osgi.core-6.0.0.jar:]
at org.osgi.util.tracker.AbstractTracked.untrack(AbstractTracked.java:341)[org.osgi.core-6.0.0.jar:]
at org.osgi.util.tracker.ServiceTracker$Tracked.serviceChanged(ServiceTracker.java:909)[org.osgi.core-6.0.0.jar:]
at org.eclipse.osgi.internal.serviceregistry.FilteredServiceListener.serviceChanged(FilteredServiceListener.java:109)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.framework.BundleContextImpl.dispatchEvent(BundleContextImpl.java:914)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:230)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:148)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.publishServiceEventPrivileged(ServiceRegistry.java:862)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.publishServiceEvent(ServiceRegistry.java:801)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.serviceregistry.ServiceRegistrationImpl.unregister(ServiceRegistrationImpl.java:222)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.ops4j.pax.web.extender.war.internal.DefaultWebAppDependencyManager.removeWebApp(DefaultWebAppDependencyManager.java:101)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.WebObserver$1.doDestroy(WebObserver.java:189)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.extender.SimpleExtension.destroy(SimpleExtension.java:71)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.extender.AbstractExtender$2.run(AbstractExtender.java:307)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)[:1.8.0_131]
at java.util.concurrent.FutureTask.run(FutureTask.java:266)[:1.8.0_131]
at org.ops4j.pax.web.extender.war.internal.extender.AbstractExtender.destroyExtension(AbstractExtender.java:333)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.extender.AbstractExtender.bundleChanged(AbstractExtender.java:191)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.eclipse.osgi.internal.framework.BundleContextImpl.dispatchEvent(BundleContextImpl.java:902)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:230)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:148)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.framework.EquinoxEventPublisher.publishBundleEventPrivileged(EquinoxEventPublisher.java:165)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.framework.EquinoxEventPublisher.publishBundleEvent(EquinoxEventPublisher.java:75)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.framework.EquinoxEventPublisher.publishBundleEvent(EquinoxEventPublisher.java:67)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.framework.EquinoxContainerAdaptor.publishModuleEvent(EquinoxContainerAdaptor.java:102)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.Module.publishEvent(Module.java:466)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.Module.doStop(Module.java:624)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.Module.stop(Module.java:488)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.decStartLevel(ModuleContainer.java:1623)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.doContainerStartLevel(ModuleContainer.java:1542)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.SystemModule.stopWorker(SystemModule.java:248)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.framework.EquinoxBundle$SystemBundle$EquinoxSystemModule.stopWorker(EquinoxBundle.java:144)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.Module.doStop(Module.java:626)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.Module.stop(Module.java:488)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.SystemModule.stop(SystemModule.java:186)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.framework.EquinoxBundle$SystemBundle$EquinoxSystemModule$1.run(EquinoxBundle.java:159)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at java.lang.Thread.run(Thread.java:748)[:1.8.0_131]

and:

2017-06-08 15:52:46,733 | WARN | Framework stop | UnregisterWebAppVisitorWC | 383 - org.ops4j.pax.web.pax-web-extender-war - 4.3.0 | Unregistration exception. Skipping.
java.lang.RuntimeException: javax.servlet.ServletException: java.lang.IllegalStateException: No WebEnvironment found: no EnvironmentLoaderListener registered?
at org.eclipse.jetty.servlet.ServletHandler.updateMappings(ServletHandler.java:1530)[148:org.eclipse.jetty.servlet:9.2.19.v20160908]
at org.eclipse.jetty.servlet.ServletHandler.setFilterMappings(ServletHandler.java:1560)[148:org.eclipse.jetty.servlet:9.2.19.v20160908]
at org.ops4j.pax.web.service.jetty.internal.JettyServerImpl$5.call(JettyServerImpl.java:597)[385:org.ops4j.pax.web.pax-web-jetty:4.3.0]
at org.ops4j.pax.web.service.jetty.internal.JettyServerImpl$5.call(JettyServerImpl.java:593)[385:org.ops4j.pax.web.pax-web-jetty:4.3.0]
at org.ops4j.pax.swissbox.core.ContextClassLoaderUtils.doWithClassLoader(ContextClassLoaderUtils.java:60)[385:org.ops4j.pax.web.pax-web-jetty:4.3.0]
at org.ops4j.pax.web.service.jetty.internal.JettyServerImpl.removeFilter(JettyServerImpl.java:592)[385:org.ops4j.pax.web.pax-web-jetty:4.3.0]
at org.ops4j.pax.web.service.jetty.internal.ServerControllerImpl$Started.removeFilter(ServerControllerImpl.java:320)[385:org.ops4j.pax.web.pax-web-jetty:4.3.0]
at org.ops4j.pax.web.service.jetty.internal.ServerControllerImpl.removeFilter(ServerControllerImpl.java:150)[385:org.ops4j.pax.web.pax-web-jetty:4.3.0]
at org.ops4j.pax.web.service.internal.HttpServiceStarted.unregisterFilter(HttpServiceStarted.java:604)[387:org.ops4j.pax.web.pax-web-runtime:4.3.0]
at org.ops4j.pax.web.service.internal.HttpServiceProxy.unregisterFilter(HttpServiceProxy.java:232)[387:org.ops4j.pax.web.pax-web-runtime:4.3.0]
at org.ops4j.pax.web.extender.war.internal.UnregisterWebAppVisitorWC.visit(UnregisterWebAppVisitorWC.java:171)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.model.WebApp.accept(WebApp.java:666)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.WebAppPublisher$WebAppDependencyListener.unregister(WebAppPublisher.java:266)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.WebAppPublisher$WebAppDependencyListener.removedService(WebAppPublisher.java:224)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.WebAppPublisher$WebAppDependencyListener.removedService(WebAppPublisher.java:135)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.osgi.util.tracker.ServiceTracker$Tracked.customizerRemoved(ServiceTracker.java:967)[org.osgi.core-6.0.0.jar:]
at org.osgi.util.tracker.ServiceTracker$Tracked.customizerRemoved(ServiceTracker.java:870)[org.osgi.core-6.0.0.jar:]
at org.osgi.util.tracker.AbstractTracked.untrack(AbstractTracked.java:341)[org.osgi.core-6.0.0.jar:]
at org.osgi.util.tracker.ServiceTracker$Tracked.serviceChanged(ServiceTracker.java:909)[org.osgi.core-6.0.0.jar:]
at org.eclipse.osgi.internal.serviceregistry.FilteredServiceListener.serviceChanged(FilteredServiceListener.java:109)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.framework.BundleContextImpl.dispatchEvent(BundleContextImpl.java:914)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:230)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:148)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.publishServiceEventPrivileged(ServiceRegistry.java:862)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.publishServiceEvent(ServiceRegistry.java:801)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.serviceregistry.ServiceRegistrationImpl.unregister(ServiceRegistrationImpl.java:222)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.ops4j.pax.web.extender.war.internal.DefaultWebAppDependencyManager.removeWebApp(DefaultWebAppDependencyManager.java:101)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.WebObserver$1.doDestroy(WebObserver.java:189)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.extender.SimpleExtension.destroy(SimpleExtension.java:71)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.extender.AbstractExtender$2.run(AbstractExtender.java:307)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)[:1.8.0_131]
at java.util.concurrent.FutureTask.run(FutureTask.java:266)[:1.8.0_131]
at org.ops4j.pax.web.extender.war.internal.extender.AbstractExtender.destroyExtension(AbstractExtender.java:333)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.ops4j.pax.web.extender.war.internal.extender.AbstractExtender.bundleChanged(AbstractExtender.java:191)[383:org.ops4j.pax.web.pax-web-extender-war:4.3.0]
at org.eclipse.osgi.internal.framework.BundleContextImpl.dispatchEvent(BundleContextImpl.java:902)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:230)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:148)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.framework.EquinoxEventPublisher.publishBundleEventPrivileged(EquinoxEventPublisher.java:165)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.framework.EquinoxEventPublisher.publishBundleEvent(EquinoxEventPublisher.java:75)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.framework.EquinoxEventPublisher.publishBundleEvent(EquinoxEventPublisher.java:67)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.framework.EquinoxContainerAdaptor.publishModuleEvent(EquinoxContainerAdaptor.java:102)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.Module.publishEvent(Module.java:466)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.Module.doStop(Module.java:624)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.Module.stop(Module.java:488)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.decStartLevel(ModuleContainer.java:1623)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.doContainerStartLevel(ModuleContainer.java:1542)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.SystemModule.stopWorker(SystemModule.java:248)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.framework.EquinoxBundle$SystemBundle$EquinoxSystemModule.stopWorker(EquinoxBundle.java:144)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.Module.doStop(Module.java:626)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.Module.stop(Module.java:488)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.container.SystemModule.stop(SystemModule.java:186)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at org.eclipse.osgi.internal.framework.EquinoxBundle$SystemBundle$EquinoxSystemModule$1.run(EquinoxBundle.java:159)[org.eclipse.osgi-3.10.101.v20150820-1432.jar:]
at java.lang.Thread.run(Thread.java:748)[:1.8.0_131]
Caused by: javax.servlet.ServletException: java.lang.IllegalStateException: No WebEnvironment found: no EnvironmentLoaderListener registered?
at org.apache.shiro.web.servlet.AbstractFilter.init(AbstractFilter.java:105)[131:org.apache.shiro.web:1.3.2]
at org.eclipse.jetty.servlet.FilterHolder.initialize(FilterHolder.java:138)[148:org.eclipse.jetty.servlet:9.2.19.v20160908]
at org.eclipse.jetty.servlet.ServletHandler.initialize(ServletHandler.java:852)[148:org.eclipse.jetty.servlet:9.2.19.v20160908]
at org.eclipse.jetty.servlet.ServletHandler.updateMappings(ServletHandler.java:1526)[148:org.eclipse.jetty.servlet:9.2.19.v20160908]
... 52 more
Caused by: java.lang.IllegalStateException: No WebEnvironment found: no EnvironmentLoaderListener registered?
at org.apache.shiro.web.util.WebUtils.getRequiredWebEnvironment(WebUtils.java:277)[131:org.apache.shiro.web:1.3.2]
at org.apache.shiro.web.servlet.ShiroFilter.init(ShiroFilter.java:73)[131:org.apache.shiro.web:1.3.2]
at org.opendaylight.aaa.shiro.filters.AAAShiroFilter.init(AAAShiroFilter.java:48)[178:org.opendaylight.aaa.shiro:0.6.0.SNAPSHOT]
at org.apache.shiro.web.servlet.AbstractShiroFilter.onFilterConfigSet(AbstractShiroFilter.java:152)[131:org.apache.shiro.web:1.3.2]
at org.apache.shiro.web.servlet.AbstractFilter.init(AbstractFilter.java:97)[131:org.apache.shiro.web:1.3.2]
... 55 more

Filing this in odlparent just because this seems to be a general Karaf 4 shutdown issue related to something with Pax Web (I'm not clear about what exactly is going on here), not specific to a particular ODL project.