Hi. I've created almost the same plugin as JobTypeColumn. There is only one difference - it shows job description instead of job type. But after i can't add this column to my list view. I have an NullPointerException after i edited my config.xml manually. java.lang.NullPointerException at hudson.model.Descriptor.newInstancesFromHeteroList(Descriptor.java:626) at hudson.util.DescribableList.rebuildHetero(DescribableList.java:164) at hudson.model.ListView.submit(ListView.java:262) at hudson.model.View.doConfigSubmit(View.java:484) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.kohsuke.stapler.Function$InstanceFunction.invoke(Function.java:185) at org.kohsuke.stapler.Function.bindAndInvoke(Function.java:101) at org.kohsuke.stapler.Function.bindAndInvokeAndServeResponse(Function.java:54) at org.kohsuke.stapler.MetaClass$1.doDispatch(MetaClass.java:74) at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:30) at org.kohsuke.stapler.Stapler.invoke(Stapler.java:492) at org.kohsuke.stapler.MetaClass$6.doDispatch(MetaClass.java:180) at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:30) at org.kohsuke.stapler.Stapler.invoke(Stapler.java:492) at org.kohsuke.stapler.Stapler.invoke(Stapler.java:408) at org.kohsuke.stapler.Stapler.service(Stapler.java:117) at javax.servlet.http.HttpServlet.service(HttpServlet.java:45) at winstone.ServletConfiguration.execute(ServletConfiguration.java:249) at winstone.RequestDispatcher.forward(RequestDispatcher.java:335) at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:378) at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:94) at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:304) at org.jvnet.hudson.plugins.monitoring.HudsonMonitoringFilter.doFilter(HudsonMonitoringFilter.java:31) at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:97) at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:86) at winstone.FilterConfiguration.execute(FilterConfiguration.java:195) at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:368) at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:47) at winstone.FilterConfiguration.execute(FilterConfiguration.java:195) at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:368) 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 winstone.FilterConfiguration.execute(FilterConfiguration.java:195) at winstone.RequestDispatcher.doFilter(RequestDispatcher.java:368) at winstone.RequestDispatcher.forward(RequestDispatcher.java:333) at winstone.RequestHandlerThread.processRequest(RequestHandlerThread.java:244) at winstone.RequestHandlerThread.run(RequestHandlerThread.java:150) at java.lang.Thread.run(Unknown Source)