Those who tried to run Wicket on JBoss AS 7 hit this:

java.lang.ClassNotFoundException: org.jboss.msc.service.ServiceName from [Module "deployment.ROOT.war:main" from Service Module Loader]
at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:190)
...
at org.apache.wicket.application.AbstractClassResolver.resolveClass(AbstractClassResolver.java:108)
at org.apache.wicket.serialize.java.JavaSerializer$ClassResolverObjectInputStream.resolveClass(JavaSerializer.java:216)

Well, the proper solution would be a special serializer, but who has time to do it.

So the quick workaround for that is to add org.jboss.msc to app's dependencies.

Add the org.jboss.msc module to dependencies. E.g. put this to META-INF/MANIFEST.MF :

Dependencies: org.jboss.msc

E.g. using this in pom.xml: 

    <build>
       ...
       <plugins>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-war-plugin</artifactId>
           <configuration>
              <archive>
                 <manifestEntries>
                    <Dependencies>org.jboss.msc</Dependencies>
                 </manifestEntries>  
              </archive>
           </configuration>
         </plugin>   
       </plugins>
    </build>