I am unable to restore a zip archive, using Hudson and Backup plugin from svn. The restore operation just hangs when trying to load the new configuration after it has been unpacked. Also, afterwards the Backup plugin is no longer installed for some reason. In the debugger (Netbeans) I get the following console output:

20.mai.2010 13:24:35 org.jvnet.hudson.plugins.backup.BackupLink getFileList
INFO: Listing files of null
20.mai.2010 13:24:35 hudson.ExpressionFactory2$JexlExpression evaluate
WARNING: Caught exception evaluating: it.fileList.isEmpty(). Reason: java.lang.reflect.InvocationTargetException
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.commons.jexl.util.PropertyExecutor.execute(PropertyExecutor.java:125)
at org.apache.commons.jexl.util.introspection.UberspectImpl$VelGetterImpl.invoke(UberspectImpl.java:314)
at org.apache.commons.jexl.parser.ASTArrayAccess.evaluateExpr(ASTArrayAccess.java:185)
at org.apache.commons.jexl.parser.ASTIdentifier.execute(ASTIdentifier.java:75)
at org.apache.commons.jexl.parser.ASTReference.execute(ASTReference.java:83)
at org.apache.commons.jexl.parser.ASTReference.value(ASTReference.java:57)
at org.apache.commons.jexl.parser.ASTReferenceExpression.value(ASTReferenceExpression.java:51)
at org.apache.commons.jexl.ExpressionImpl.evaluate(ExpressionImpl.java:80)
at hudson.ExpressionFactory2$JexlExpression.evaluate(ExpressionFactory2.java:72)
at org.apache.commons.jelly.tags.core.CoreTagLibrary$3.run(CoreTagLibrary.java:134)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.kohsuke.stapler.jelly.CallTagLibScript$1.run(CallTagLibScript.java:75)
at org.apache.commons.jelly.tags.define.InvokeBodyTag.doTag(InvokeBodyTag.java:91)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:270)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.tags.core.CoreTagLibrary$1.run(CoreTagLibrary.java:98)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.tags.core.CoreTagLibrary$2.run(CoreTagLibrary.java:105)
at org.kohsuke.stapler.jelly.CallTagLibScript.run(CallTagLibScript.java:96)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.kohsuke.stapler.jelly.CallTagLibScript$1.run(CallTagLibScript.java:75)
at org.apache.commons.jelly.tags.define.InvokeBodyTag.doTag(InvokeBodyTag.java:91)
at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:270)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:76)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:76)
at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:76)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:76)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.kohsuke.stapler.jelly.ReallyStaticTagLibrary$1.run(ReallyStaticTagLibrary.java:76)
at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
at org.apache.commons.jelly.tags.core.CoreTagLibrary$2.run(CoreTagLibrary.java:105)
at org.kohsuke.stapler.jelly.CallTagLibScript.run(CallTagLibScript.java:96)
at org.apache.commons.jelly.tags.core.CoreTagLibrary$2.run(CoreTagLibrary.java:105)
at org.kohsuke.stapler.jelly.DefaultScriptInvoker.invokeScript(DefaultScriptInvoker.java:40)
at org.kohsuke.stapler.jelly.DefaultScriptInvoker.invokeScript(DefaultScriptInvoker.java:30)
at org.kohsuke.stapler.jelly.JellyFacet$1.dispatch(JellyFacet.java:59)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:525)
at org.kohsuke.stapler.MetaClass$12.dispatch(MetaClass.java:319)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:525)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:441)
at org.kohsuke.stapler.Stapler.service(Stapler.java:123)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1093)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:94)
at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:86)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:47)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84)
at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:164)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:360)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:726)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:206)
at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
at org.mortbay.jetty.Server.handle(Server.java:324)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:828)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:514)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:395)
at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:450)
Caused by: java.lang.NullPointerException
at java.io.File.<init>(File.java:222)
at org.jvnet.hudson.plugins.backup.BackupLink.getFileList(BackupLink.java:151)
... 76 more
20.mai.2010 13:24:50 org.jvnet.hudson.plugins.backup.BackupLink doSaveSettings
INFO: BackupLink.doSaveSetting
20.mai.2010 13:24:50 org.jvnet.hudson.plugins.backup.BackupPluginImpl saveConfiguration
INFO: Saving configuration...
20.mai.2010 13:24:50 org.jvnet.hudson.plugins.backup.BackupLink doSaveSettings
INFO: Backup configuration saved.
20.mai.2010 13:24:59 org.jvnet.hudson.plugins.backup.BackupLink doSaveSettings
INFO: BackupLink.doSaveSetting
20.mai.2010 13:24:59 org.jvnet.hudson.plugins.backup.BackupPluginImpl saveConfiguration
INFO: Saving configuration...
20.mai.2010 13:24:59 org.jvnet.hudson.plugins.backup.BackupLink doSaveSettings
INFO: Backup configuration saved.
20.mai.2010 13:25:02 org.jvnet.hudson.plugins.backup.BackupLink getFileList
INFO: Listing files of C:\Users\arvek\Hudson Backup
20.mai.2010 13:25:02 org.jvnet.hudson.plugins.backup.BackupLink getFileList
INFO: Listing files of C:\Users\arvek\Hudson Backup
20.mai.2010 13:25:05 org.jvnet.hudson.plugins.backup.BackupLink doRestoreFile
INFO: Selected file : backup_20100520_1104.zip
Exception in thread "pool-6-thread-1" java.lang.NoClassDefFoundError: org/jvnet/hudson/plugins/backup/utils/FakeObject
at org.jvnet.hudson.plugins.backup.utils.RestoreTask.run(RestoreTask.java:127)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.ClassNotFoundException: org.jvnet.hudson.plugins.backup.utils.FakeObject
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
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)
... 2 more