We have become very interested in VWS
                        and are trying to migrate our application from
                        Tomcat. As the first step, following the
                        documentation, I dropped our application WAR
                        (which works on Tomcat 6) in the pickup
                        directory. According to the log, VWS
                        installs the WAR, but fails to start it.
                      The error messages don't provide any hint as
                        to the root cause: 
                      
                        [2010-11-14 16:12:05.472]
                          fs-watcher                   <HD0001I>
                          Hot deployer processing 'CREATED' event for
                          file 'EMA-Server.war'.
                        [2010-11-14 16:12:06.122]
                          fs-watcher                   <DE0000I>
                          Installing bundle 'EMA-Server' version
                          '0.0.0'.
                        [2010-11-14 16:12:09.285]
                          fs-watcher                   <DE0001I>
                          Installed bundle 'EMA-Server' version '0.0.0'.
                        [2010-11-14 16:12:09.311]
                          fs-watcher                   <DE0004I>
                          Starting bundle 'EMA-Server' version '0.0.0'.
                        [2010-11-14 16:12:09.316]
                          Thread-3                     <WE0000I>
                          Starting web bundle 'EMA-Server' version
                          '0.0.0' with context path '/EMA-Server'.
                        [2010-11-14 16:12:14.696]
                          Thread-3                     <WE0005E>
                          Failed to start web bundle 'EMA-Server'
                          version '0.0.0': consult the serviceability
                          log for further details.
                        [2010-11-14 16:12:14.701]
                          start-signalling-4           <DE0006E>
                          Start failed for bundle 'EMA-Server' version
                          '0.0.0'.
                          org.eclipse.virgo.kernel.deployer.core.DeploymentException:
                          W
                        eb application failed to start
                                at
org.eclipse.virgo.web.core.internal.WebBundleLifecycleListener.onStarted(WebBundleLifecycleListener.java:129)
                                at
org.eclipse.virgo.kernel.install.artifact.internal.ArtifactStateMonitor.onStarted(ArtifactStateMonitor.java:205)
                                at
org.eclipse.virgo.kernel.install.artifact.internal.AbstractInstallArtifact.asyncStartSucceeded(AbstractInstallArtifact.java:273)
                                at
org.eclipse.virgo.kernel.install.artifact.internal.AbstractInstallArtifact.access$0(AbstractInstallArtifact.java:270)
                                at
org.eclipse.virgo.kernel.install.artifact.internal.AbstractInstallArtifact$StateMonitorSignal.signalSuccessfulCompletion(AbstractInstallArtifact.java:223)
                                at
org.eclipse.virgo.kernel.core.internal.BundleStartTracker$1.run(BundleStartTracker.java:140)
                                at
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
                                at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
                                at
                          java.lang.Thread.run(Thread.java:619)
                        Caused by:
                          org.eclipse.gemini.web.core.WebApplicationStartFailedException:
                          org.eclipse.gemini.web.core.spi.ServletContainerException:
                          Web application at '/EMA-Server' failed to sta
                        rt. Check the logs for more details.
                                at
org.eclipse.gemini.web.internal.StandardWebApplication.start(StandardWebApplication.java:107)
                                at
org.eclipse.virgo.web.core.internal.WebBundleLifecycleListener.onStarted(WebBundleLifecycleListener.java:120)
                                ... 8 common frames omitted
                        Caused by:
                          org.eclipse.gemini.web.core.spi.ServletContainerException:
                          Web application at '/EMA-Server' failed to
                          start. Check the logs for more details.
                                at
org.eclipse.gemini.web.tomcat.internal.TomcatServletContainer.startWebApplication(TomcatServletContainer.java:123)
                                at
org.eclipse.gemini.web.internal.StandardWebApplication.start(StandardWebApplication.java:90)
                                ... 9 common frames omitted 
                      
                      While searching in the documentation, I came
                        across the following note. It got my attention,
                        as we use the TomcatInstrumentableClassLoader in
                        the Tomcat's context.xml packaged in our WAR
                        file.
                       Is TomcatInstrumentableClassLoader 
                        considered a "Custom class loader" in VWS? If
                        yes, is there any workaround for it? Here's the
                        line from our context.xml file: