title: Why is my Jenkins throwing 'no such method found' exceptions after restart?
body: <p>Jenkins was restarted. I lost all the projects that had used 'jenkins pipeline'. I see the directories on the server itself, but from the looks of it, Jenkins fails to load them; I don't see the projects on the UI.</p>
  
  <p>Below is the error I see repeating itself. What could be the reason? I am on Jenkins 2.7.4.</p>
  
  <pre><code>May 07, 2018 2:32:00 PM com.cloudbees.hudson.plugins.folder.computed.FolderCron doRun
  WARNING: Cron thread throw an exception
  java.lang.NoSuchMethodError: jenkins.model.Jenkins.allItems(Ljava/lang/Class;)Ljava/lang/Iterable;
      at com.cloudbees.hudson.plugins.folder.computed.FolderCron.checkTriggers(FolderCron.java:117)
      at com.cloudbees.hudson.plugins.folder.computed.FolderCron.doRun(FolderCron.java:101)
      at hudson.triggers.SafeTimerTask.run(SafeTimerTask.java:50)
      at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
      at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
      at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
      at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
      at java.lang.Thread.run(Thread.java:745)
  
  java.lang.NoSuchMethodError: jenkins.model.Jenkins.allItems(Ljava/lang/Class;)Ljava/lang/Iterable;
      at com.cloudbees.hudson.plugins.folder.computed.FolderCron.checkTriggers(FolderCron.java:117)
      at com.cloudbees.hudson.plugins.folder.computed.FolderCron.doRun(FolderCron.java:101)
      at hudson.triggers.SafeTimerTask.run(SafeTimerTask.java:50)
      at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
      at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
      at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
      at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
      at java.lang.Thread.run(Thread.java:745)
  </code></pre>