Hudson fails to start, even after clean installation. The catalina.log contains this Stacktrace:
Exception in thread "hudson initialization thread" java.lang.NoClassDefFoundError: hudson/model/RootAction
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632)
at java.lang.ClassLoader.defineClass(ClassLoader.java:616)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
at hudson.PluginManager$UberClassLoader.findClass(PluginManager.java:380)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
at net.java.sezpoz.IndexItem.element(IndexItem.java:109)
at hudson.ExtensionFinder$Sezpoz.findExtensions(ExtensionFinder.java:87)
at hudson.ExtensionList.load(ExtensionList.java:190)
at hudson.ExtensionList.ensureLoaded(ExtensionList.java:176)
at hudson.ExtensionList.iterator(ExtensionList.java:107)
at hudson.ExtensionList.load(ExtensionList.java:189)
at hudson.ExtensionList.ensureLoaded(ExtensionList.java:176)
at hudson.ExtensionList.iterator(ExtensionList.java:107)
at hudson.model.Hudson.<init>(Hudson.java:547)