title: Upgrading Hudson to Jenkins: 500 error
body: <p>I tried to upgrade from Hudson to Jenkins and I'm getting a "Status Code: 500 error" on the main page. I put in a bug report here: <a href="https://issues.jenkins-ci.org/browse/JENKINS-15309" rel="nofollow">https://issues.jenkins-ci.org/browse/JENKINS-15309</a> but no one has responded. </p>
  
  <p>Anyone else have an idea of what is going on? I'd really like to convert from Hudson to Jenkins. </p>
  
  <p>Partial stacktrace:</p>
  
  <pre><code>Status Code: 500
  Exception: org.apache.commons.jelly.JellyTagException: jar:file:/appserv/devimat/hudson/war/WEB-INF/lib/jenkins-core-1.483.jar!/hudson/model/View/index.jelly:44:43: &lt;st:include&gt; Cannot invoke method isEmpty() on null object
  Stacktrace:
  
  javax.servlet.ServletException: org.apache.commons.jelly.JellyTagException: jar:file:/appserv/devimat/hudson/war/WEB-INF/lib/jenkins-core-1.483.jar!/hudson/model/View/index.jelly:44:43: &lt;st:include&gt; Cannot invoke method isEmpty() on null object
  at org.kohsuke.stapler.jelly.JellyClassTearOff.serveIndexJelly(JellyClassTearOff.java:112)
  at org.kohsuke.stapler.jelly.JellyFacet.handleIndexRequest(JellyFacet.java:127)
  at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:563)
  at org.kohsuke.stapler.Stapler.invoke(Stapler.java:659)
  at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:625)
  at org.kohsuke.stapler.Stapler.invoke(Stapler.java:659)
  at org.kohsuke.stapler.Stapler.invoke(Stapler.java:488)
  at org.kohsuke.stapler.Stapler.service(Stapler.java:162)
  [...]
  
  Caused by: org.apache.commons.jelly.JellyTagException: jar:file:/appserv/devimat/hudson/war/WEB-INF/lib/jenkins-core-1.483.jar!/hudson/model/View/index.jelly:44:43: &lt;st:include&gt; Cannot invoke method isEmpty() on null object
  at org.apache.commons.jelly.impl.TagScript.handleException(TagScript.java:716)
  at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:282)
  at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95)
  at org.kohsuke.stapler.jelly.CallTagLibScript$1.run(CallTagLibScript.java:98)
  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)
  [...]
  </code></pre>