tomcat搭建遇到的问题：

最近使用jdk1.6.0_10加tomcat6.0.18搭建了一个jsp的应用环境！可是tomcat每次启动都报错！
高人帮忙看下吧，谢谢！
日志如下：
Oct 14, 2008 3:41:29 PM org.apache.catalina.core.AprLifecycleListener init
INFO: Loaded APR based Apache Tomcat Native library 1.1.14.
Oct 14, 2008 3:41:29 PM org.apache.catalina.core.AprLifecycleListener init
INFO: APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true].
Oct 14, 2008 3:41:29 PM org.apache.coyote.http11.Http11AprProtocol init
INFO: Initializing Coyote HTTP/1.1 on http-8080
Oct 14, 2008 3:41:29 PM org.apache.coyote.ajp.AjpAprProtocol init
INFO: Initializing Coyote AJP/1.3 on ajp-8009
Oct 14, 2008 3:41:29 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 815 ms
Oct 14, 2008 3:41:29 PM org.apache.catalina.core.StandardService start
INFO: Starting service Catalina
Oct 14, 2008 3:41:29 PM org.apache.catalina.core.StandardEngine start
INFO: Starting Servlet Engine: Apache Tomcat/6.0.18
Loading file:/usr/local/apache-tomcat-6.0.18/webapps/51widgets/WEB-INF/classes/system.properties
Oct 14, 2008 3:41:31 PM org.apache.catalina.core.StandardContext start
严重: Error filterStart
Oct 14, 2008 3:41:31 PM org.apache.catalina.core.StandardContext start
严重: Context [] startup failed due to previous errors
java.lang.NullPointerException
at com.liferay.portal.events.EventsProcessor.process(EventsProcessor.java:73)
at com.liferay.portal.util.InitUtil.init(InitUtil.java:38)
at com.liferay.portal.servlet.MainServlet.<clinit>(MainServlet.java:114)
at sun.misc.Unsafe.ensureClassInitialized(Native Method)
at sun.reflect.UnsafeFieldAccessorFactory.newFieldAccessor(UnsafeFieldAccessorFactory.java:25)
at sun.reflect.ReflectionFactory.newFieldAccessor(ReflectionFactory.java:122)
at java.lang.reflect.Field.acquireFieldAccessor(Field.java:918)
at java.lang.reflect.Field.getFieldAccessor(Field.java:899)
at java.lang.reflect.Field.set(Field.java:657)
at org.apache.catalina.loader.WebappClassLoader.clearReferences(WebappClassLoader.java:1644)
at org.apache.catalina.loader.WebappClassLoader.stop(WebappClassLoader.java:1524)
at org.apache.catalina.loader.WebappLoader.stop(WebappLoader.java:707)
at org.apache.catalina.core.StandardContext.stop(StandardContext.java:4557)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4387)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:719)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
at org.apache.catalina.core.StandardService.start(StandardService.java:516)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
at org.apache.catalina.startup.Catalina.start(Catalina.java:578)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)
Oct 14, 2008 3:41:32 PM org.apache.catalina.core.StandardContext start
严重: Error listenerStart
Oct 14, 2008 3:41:32 PM org.apache.catalina.core.StandardContext start
严重: Context [/51widgets] startup failed due to previous errors
Loading file:/usr/local/apache-tomcat-6.0.18/webapps/51widgets/WEB-INF/classes/system.properties
Oct 14, 2008 3:41:33 PM org.apache.coyote.http11.Http11AprProtocol start
信息: Starting Coyote HTTP/1.1 on http-8080
Oct 14, 2008 3:41:33 PM org.apache.coyote.ajp.AjpAprProtocol start
信息: Starting Coyote AJP/1.3 on ajp-8009
Oct 14, 2008 3:41:33 PM org.apache.catalina.startup.Catalina start
信息: Server startup in 3926 ms