web app not deploying after custom data type creation

[Jennifer Kroll]

Hello,

I tried implementing the example custom data type ext.xsd via https://wiki.xnat.org/display/XNAT16/Customizing+Data+Types and video tutorial. All went well until redeploying the XNAT web app. I get an "http: 404, resource not found" error. The turbine.log is empty as well as the localhost .<date>.log. This is what the catalina.<date>.log says:

Feb 3, 2014 8:36:27 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-bio-8080"]
Feb 3, 2014 8:36:27 AM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 3423 ms
Feb 3, 2014 8:36:27 AM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
Feb 3, 2014 8:36:27 AM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.26
Feb 3, 2014 8:36:27 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory /var/lib/tomcat7/webapps/xnat
Feb 3, 2014 8:36:28 AM org.apache.catalina.core.ContainerBase addChildInternal
SEVERE: ContainerBase.addChild: start:
org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/xnat]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:895)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:871)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:615)
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1095)
    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1617)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
    at java.util.concurrent.FutureTask.run(FutureTask.java:166)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:701)
Caused by: java.lang.UnsupportedClassVersionError: org/nrg/xnat/security/XnatSessionEventPublisher : Unsupported major.minor version 51.0 (unable to load class org.nrg.xnat.security.XnatSessionEventPublisher)
    at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2840)
    at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1160)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1668)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1546)
    at org.apache.catalina.startup.WebAnnotationSet.loadClassAnnotation(WebAnnotationSet.java:144)
    at org.apache.catalina.startup.WebAnnotationSet.loadApplicationListenerAnnotations(WebAnnotationSet.java:73)
    at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:56)
    at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:381)
    at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:858)
    at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:345)
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
    at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5161)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 11 more
Feb 3, 2014 8:36:28 AM org.apache.catalina.startup.HostConfig deployDirectory
SEVERE: Error deploying web application directory /var/lib/tomcat7/webapps/xnat
java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/xnat]]
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:898)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:871)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:615)
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1095)
    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1617)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
    at java.util.concurrent.FutureTask.run(FutureTask.java:166)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:701)
Feb 3, 2014 8:36:28 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory /var/lib/tomcat7/webapps/ROOT
Feb 3, 2014 8:36:29 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-bio-8080"]
Feb 3, 2014 8:36:29 AM org.apache.catalina.startup.Catalina start
INFO: Server startup in 2072 ms


This kind of debugging is beyond my comprehension right now. I'm using XNAT1.6.1 on VM. Any helping getting this working is greatly appreciated. Thanks!
~Jen