If I setup tomcat with bundled webapps there is no error. But when I add my 
webapp and restart tomcat I saw following exception in the log;

2004-02-19 18:34:11 StandardContext[/balancer]Exception starting filter 
BalancerFilter
java.lang.NoClassDefFoundError: org/apache/commons/digester/Digester
        at org.apache.webapp.balancer.RulesParser.createDigester
(RulesParser.java:107)
        at org.apache.webapp.balancer.RulesParser.<init>(RulesParser.java:85)
        at org.apache.webapp.balancer.BalancerFilter.init
(BalancerFilter.java:121)
        at org.apache.catalina.core.ApplicationFilterConfig.getFilter
(ApplicationFilterConfig.java:272)
        at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef
(ApplicationFilterConfig.java:355)
        at org.apache.catalina.core.ApplicationFilterConfig.<init>
(ApplicationFilterConfig.java:126)
        at org.apache.catalina.core.StandardContext.filterStart
(StandardContext.java:3646)
        at org.apache.catalina.core.StandardContext.start
(StandardContext.java:4275)
        at org.apache.catalina.core.ContainerBase.addChildInternal
(ContainerBase.java:866)
        at org.apache.catalina.core.ContainerBase.addChild
(ContainerBase.java:850)
        at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:638)
        at org.apache.catalina.core.StandardHostDeployer.install
(StandardHostDeployer.java:320)
        at org.apache.catalina.core.StandardHost.install(StandardHost.java:875)
        at org.apache.catalina.startup.HostConfig.deployDirectories
(HostConfig.java:727)
        at org.apache.catalina.startup.HostConfig.deployApps
(HostConfig.java:477)
        at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1008)
        at org.apache.catalina.startup.HostConfig.lifecycleEvent
(HostConfig.java:394)
        at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent
(LifecycleSupport.java:166)
        at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1133)
        at org.apache.catalina.core.StandardHost.start(StandardHost.java:832)
        at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1125)
        at org.apache.catalina.core.StandardEngine.start
(StandardEngine.java:518)
        at org.apache.catalina.core.StandardService.start
(StandardService.java:519)
        at org.apache.catalina.core.StandardServer.start
(StandardServer.java:2345)
        at org.apache.catalina.startup.Catalina.start(Catalina.java:598)
        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:324)
        at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:297)
        at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:398)

I think this exception is about balancer web app. I checked server/lib 
directory and found commons-digester.jar in it. I don't know why tomcat 
couldn't find this class. What is this problem?

   One more thing, there isn't any Webapps:Balancer item in Component listbox 
of tomcat bug report form. So I choosed 'Unknown'

Thanks,

Deniz TATAR