error when trying to run a wicket application under eclipse

Question

i am trying to build a web application using wicket. but whenever i try to run, i get the following error

 SEVERE: StandardWrapper.Throwable java.lang.NoSuchMethodError:
 org.apache.wicket.util.lang.Args.notNull(Ljava/lang/Object;Ljava/lang/String;)V
    at
 org.apache.wicket.request.resource.ResourceReference.<init>(ResourceReference.java:73)
    at
 org.apache.wicket.request.resource.ResourceReference.<init>(ResourceReference.java:89)
    at
 org.apache.wicket.request.resource.PackageResourceReference.<init>(PackageResourceReference.java:69)
    at
 org.apache.wicket.extensions.ajax.markup.html.form.upload.UploadProgressBar.<clinit>(UploadProgressBar.java:110)
    at
 org.apache.wicket.extensions.ajax.markup.html.form.upload.UploadProgressBar$ComponentInitializer.init(UploadProgressBar.java:92)
    at org.apache.wicket.extensions.Initializer.init(Initializer.java:36)
    at
 org.apache.wicket.Application.callInitializers(Application.java:788)
    at
 org.apache.wicket.Application.initializeComponents(Application.java:625)
    at
 org.apache.wicket.protocol.http.WicketFilter.init(WicketFilter.java:575)
    at
 org.apache.wicket.protocol.http.WicketServlet.init(WicketServlet.java:194)
    at javax.servlet.GenericServlet.init(GenericServlet.java:160)   at
 org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1266)
    at
 org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1185)
    at
 org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1080)
    at
 org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5027)
    at
 org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5314)
    at
 org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at
 org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at
 org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)     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) 

Can anybody please explain the reason for the error?

Answer 1

Since you are using Wicket-Extensions, make sure that the versions of all Wicket dependencies match. Ie if some additional dependencies are not updated yet, you should downgrade your main Wicket version.