Answers: <p>So I feel stupid now, but I solved it. I took another look at the error and found <code>Caused by: java.io.IOException: Unable to read /Users/Shared/Jenkins/Home/config-history/nodes/build2/2018-06-13_11-41-13/history.xml
      at hudson.XmlFile.read(XmlFile.java:144)</code></p>
  
  <p>I went to the file and the found that the first row said <code>&lt;?xml version='1.1' encoding='UTF-8'?&gt;</code>. I also noticed that the error message said </p>
  
  <pre><code>Caused by: org.xmlpull.v1.XmlPullParserException: only 1.0 is supported as &lt;?xml version not '1.1' (position: START_DOCUMENT seen &lt;?xml version=\'1.1\'... @1:19) 
      at org.xmlpull.mxp1.MXParser.parseXmlDeclWithVersion(MXParser.java:2608)
  </code></pre>
  
  <p>I changed the <code>&lt;?xml version='1.1&gt;</code> to <code>&lt;?xml version='1.0&gt;</code>, saved the file and restarted jenkins using</p>
  
  <pre><code>sudo launchctl stop org.jenkins-ci
  sudo launchctl unload /Library/LaunchDaemons/org.jenkins-ci.plist
  sudo launchctl load /Library/LaunchDaemons/org.jenkins-ci.plist
  </code></pre>
  
Answers: CC BY-SA 4.0
Answers: 2018-06-18T14:05:47.187Z
Answers: 2018-06-18T14:05:47.187Z
Answers: Viktor
Body: <p>A week ago I had to restart our Jenkins, I did so via "jenkins url"/restart At first it was stuck on "please wait while Jenkins is restarting" for like...1.5 days, so I figured something was wrong.</p>
  
  <p>I troubleshooted and restarted the service (daemon) itself as <a href="https://stackoverflow.com/questions/17344061/please-wait-while-jenkins-is-restarting-waiting-long">this</a> post suggested. After the manual restart the jenkins page spat out this error </p>
  
  <pre><code>    hudson.util.HudsonFailedToLoad: org.jvnet.hudson.reactor.ReactorException: java.lang.RuntimeException: Unable to read history for build2
      at hudson.WebAppMain$3.run(WebAppMain.java:239)
  Caused by: org.jvnet.hudson.reactor.ReactorException: java.lang.RuntimeException: Unable to read history for build2
      at org.jvnet.hudson.reactor.Reactor.execute(Reactor.java:269)
      at jenkins.InitReactorRunner.run(InitReactorRunner.java:44)
      at jenkins.model.Jenkins.executeReactor(Jenkins.java:969)
      at jenkins.model.Jenkins.&lt;init&gt;(Jenkins.java:850)
      at hudson.model.Hudson.&lt;init&gt;(Hudson.java:85)
      at hudson.model.Hudson.&lt;init&gt;(Hudson.java:81)
      at hudson.WebAppMain$3.run(WebAppMain.java:227)
  Caused by: java.lang.RuntimeException: Unable to read history for build2
      at hudson.plugins.jobConfigHistory.FileHistoryDao.getRevisions(FileHistoryDao.java:748)
      at hudson.plugins.jobConfigHistory.FileHistoryDao.hasDuplicateHistory(FileHistoryDao.java:804)
      at hudson.plugins.jobConfigHistory.ComputerHistoryListener.onChange(ComputerHistoryListener.java:94)
      at hudson.plugins.jobConfigHistory.ComputerHistoryListener.onConfigurationChange(ComputerHistoryListener.java:52)
      at hudson.model.AbstractCIBase.updateComputerList(AbstractCIBase.java:209)
      at jenkins.model.Jenkins.updateComputerList(Jenkins.java:1293)
      at jenkins.model.Nodes$7.run(Nodes.java:304)
      at hudson.model.Queue._withLock(Queue.java:1312)
      at hudson.model.Queue.withLock(Queue.java:1189)
      at jenkins.model.Nodes.load(Nodes.java:295)
      at jenkins.model.Jenkins$17.run(Jenkins.java:2739)
      at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:169)
      at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:282)
      at jenkins.model.Jenkins$8.runTask(Jenkins.java:958)
      at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:210)
      at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:117)
      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)
  Caused by: java.io.IOException: Unable to read /Users/Shared/Jenkins/Home/config-history/nodes/build2/2018-06-13_11-41-13/history.xml
      at hudson.XmlFile.read(XmlFile.java:144)
      at hudson.plugins.jobConfigHistory.FileHistoryDao.getRevisions(FileHistoryDao.java:746)
      ... 18 more
  Caused by: com.thoughtworks.xstream.io.StreamException:  : only 1.0 is supported as &lt;?xml version not '1.1' (position: START_DOCUMENT seen &lt;?xml version=\'1.1\'... @1:19) 
      at com.thoughtworks.xstream.io.xml.XppReader.pullNextEvent(XppReader.java:124)
      at com.thoughtworks.xstream.io.xml.AbstractPullReader.readRealEvent(AbstractPullReader.java:148)
      at com.thoughtworks.xstream.io.xml.AbstractPullReader.readEvent(AbstractPullReader.java:141)
      at com.thoughtworks.xstream.io.xml.AbstractPullReader.move(AbstractPullReader.java:118)
      at com.thoughtworks.xstream.io.xml.AbstractPullReader.moveDown(AbstractPullReader.java:103)
      at com.thoughtworks.xstream.io.xml.XppReader.&lt;init&gt;(XppReader.java:63)
      at com.thoughtworks.xstream.io.xml.AbstractXppDriver.createReader(AbstractXppDriver.java:54)
      at com.thoughtworks.xstream.io.xml.AbstractXppDriver.createReader(AbstractXppDriver.java:65)
      at com.thoughtworks.xstream.XStream.fromXML(XStream.java:1053)
      at hudson.XmlFile.read(XmlFile.java:142)
      ... 19 more
  Caused by: org.xmlpull.v1.XmlPullParserException: only 1.0 is supported as &lt;?xml version not '1.1' (position: START_DOCUMENT seen &lt;?xml version=\'1.1\'... @1:19) 
      at org.xmlpull.mxp1.MXParser.parseXmlDeclWithVersion(MXParser.java:2608)
      at org.xmlpull.mxp1.MXParser.parseXmlDecl(MXParser.java:2592)
      at org.xmlpull.mxp1.MXParser.parsePI(MXParser.java:2466)
      at org.xmlpull.mxp1.MXParser.parseProlog(MXParser.java:1447)
      at org.xmlpull.mxp1.MXParser.nextImpl(MXParser.java:1395)
      at org.xmlpull.mxp1.MXParser.next(MXParser.java:1093)
      at com.thoughtworks.xstream.io.xml.XppReader.pullNextEvent(XppReader.java:109)
      ... 28 more
  </code></pre>
  
  <p>I guess it has to do with a slave not restarting correctly but I ain't sure, does anyone have any guesses what my next steps should be? I have already removed all the plugins for jenkins to no avail. I have also tried to start the jenkins.war file through Java, but it just says that putty can't be started and aborts. The jenkins is running on a MAC</p>
  
  <p>Sorry if the solution is super obvious, I haven't got that much experience with Jenkins. Thanks!</p>
  
Tags: <jenkins>
Title: Jenkins fails to start after a restart with "hudson.util.HudsonFailedToLoad: org.jvnet.hudson.reactor.ReactorException"
UserDisplayName: Viktor
ThreadText: # Jenkins fails to start after a restart with "hudson.util.HudsonFailedToLoad: org.jvnet.hudson.reactor.ReactorException"
  
  (Asked by: username_0 on 2018-06-18)
  
  A week ago I had to restart our Jenkins, I did so via "jenkins url"/restart At first it was stuck on "please wait while Jenkins is restarting" for like...1.5 days, so I figured something was wrong.
  
  I troubleshooted and restarted the service (daemon) itself as [this](https://stackoverflow.com/questions/17344061/please-wait-while-jenkins-is-restarting-waiting-long) post suggested. After the manual restart the jenkins page spat out this error
  
  ```
      hudson.util.HudsonFailedToLoad: org.jvnet.hudson.reactor.ReactorException: java.lang.RuntimeException: Unable to read history for build2
      at hudson.WebAppMain$3.run(WebAppMain.java:239)
  Caused by: org.jvnet.hudson.reactor.ReactorException: java.lang.RuntimeException: Unable to read history for build2
      at org.jvnet.hudson.reactor.Reactor.execute(Reactor.java:269)
      at jenkins.InitReactorRunner.run(InitReactorRunner.java:44)
      at jenkins.model.Jenkins.executeReactor(Jenkins.java:969)
      at jenkins.model.Jenkins.<init>(Jenkins.java:850)
      at hudson.model.Hudson.<init>(Hudson.java:85)
      at hudson.model.Hudson.<init>(Hudson.java:81)
      at hudson.WebAppMain$3.run(WebAppMain.java:227)
  Caused by: java.lang.RuntimeException: Unable to read history for build2
      at hudson.plugins.jobConfigHistory.FileHistoryDao.getRevisions(FileHistoryDao.java:748)
      at hudson.plugins.jobConfigHistory.FileHistoryDao.hasDuplicateHistory(FileHistoryDao.java:804)
      at hudson.plugins.jobConfigHistory.ComputerHistoryListener.onChange(ComputerHistoryListener.java:94)
      at hudson.plugins.jobConfigHistory.ComputerHistoryListener.onConfigurationChange(ComputerHistoryListener.java:52)
      at hudson.model.AbstractCIBase.updateComputerList(AbstractCIBase.java:209)
      at jenkins.model.Jenkins.updateComputerList(Jenkins.java:1293)
      at jenkins.model.Nodes$7.run(Nodes.java:304)
      at hudson.model.Queue._withLock(Queue.java:1312)
      at hudson.model.Queue.withLock(Queue.java:1189)
      at jenkins.model.Nodes.load(Nodes.java:295)
      at jenkins.model.Jenkins$17.run(Jenkins.java:2739)
      at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:169)
      at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:282)
      at jenkins.model.Jenkins$8.runTask(Jenkins.java:958)
      at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:210)
      at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:117)
      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)
  Caused by: java.io.IOException: Unable to read /Users/Shared/Jenkins/Home/config-history/nodes/build2/2018-06-13_11-41-13/history.xml
      at hudson.XmlFile.read(XmlFile.java:144)
      at hudson.plugins.jobConfigHistory.FileHistoryDao.getRevisions(FileHistoryDao.java:746)
      ... 18 more
  Caused by: com.thoughtworks.xstream.io.StreamException:  : only 1.0 is supported as <?xml version not '1.1' (position: START_DOCUMENT seen <?xml version=\'1.1\'... @1:19) 
      at com.thoughtworks.xstream.io.xml.XppReader.pullNextEvent(XppReader.java:124)
      at com.thoughtworks.xstream.io.xml.AbstractPullReader.readRealEvent(AbstractPullReader.java:148)
      at com.thoughtworks.xstream.io.xml.AbstractPullReader.readEvent(AbstractPullReader.java:141)
      at com.thoughtworks.xstream.io.xml.AbstractPullReader.move(AbstractPullReader.java:118)
      at com.thoughtworks.xstream.io.xml.AbstractPullReader.moveDown(AbstractPullReader.java:103)
      at com.thoughtworks.xstream.io.xml.XppReader.<init>(XppReader.java:63)
      at com.thoughtworks.xstream.io.xml.AbstractXppDriver.createReader(AbstractXppDriver.java:54)
      at com.thoughtworks.xstream.io.xml.AbstractXppDriver.createReader(AbstractXppDriver.java:65)
      at com.thoughtworks.xstream.XStream.fromXML(XStream.java:1053)
      at hudson.XmlFile.read(XmlFile.java:142)
      ... 19 more
  Caused by: org.xmlpull.v1.XmlPullParserException: only 1.0 is supported as <?xml version not '1.1' (position: START_DOCUMENT seen <?xml version=\'1.1\'... @1:19) 
      at org.xmlpull.mxp1.MXParser.parseXmlDeclWithVersion(MXParser.java:2608)
      at org.xmlpull.mxp1.MXParser.parseXmlDecl(MXParser.java:2592)
      at org.xmlpull.mxp1.MXParser.parsePI(MXParser.java:2466)
      at org.xmlpull.mxp1.MXParser.parseProlog(MXParser.java:1447)
      at org.xmlpull.mxp1.MXParser.nextImpl(MXParser.java:1395)
      at org.xmlpull.mxp1.MXParser.next(MXParser.java:1093)
      at com.thoughtworks.xstream.io.xml.XppReader.pullNextEvent(XppReader.java:109)
      ... 28 more
  
  ```
  
  I guess it has to do with a slave not restarting correctly but I ain't sure, does anyone have any guesses what my next steps should be? I have already removed all the plugins for jenkins to no avail. I have also tried to start the jenkins.war file through Java, but it just says that putty can't be started and aborts. The jenkins is running on a MAC
  
  Sorry if the solution is super obvious, I haven't got that much experience with Jenkins. Thanks!
  
  **Tags:** jenkins
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_0 on 2018-06-18. Score: 1
  
  So I feel stupid now, but I solved it. I took another look at the error and found `Caused by: java.io.IOException: Unable to read /Users/Shared/Jenkins/Home/config-history/nodes/build2/2018-06-13_11-41-13/history.xml
  at hudson.XmlFile.read(XmlFile.java:144)`
  
  I went to the file and the found that the first row said `<?xml version='1.1' encoding='UTF-8'?>`. I also noticed that the error message said
  
  ```
  Caused by: org.xmlpull.v1.XmlPullParserException: only 1.0 is supported as <?xml version not '1.1' (position: START_DOCUMENT seen <?xml version=\'1.1\'... @1:19) 
      at org.xmlpull.mxp1.MXParser.parseXmlDeclWithVersion(MXParser.java:2608)
  
  ```
  
  I changed the `<?xml version='1.1>` to `<?xml version='1.0>`, saved the file and restarted jenkins using
  
  ```
  sudo launchctl stop org.jenkins-ci
  sudo launchctl unload /Library/LaunchDaemons/org.jenkins-ci.plist
  sudo launchctl load /Library/LaunchDaemons/org.jenkins-ci.plist
  
  ```
  
  
  ---
  
  