title: Mylyn jenkins connector gives always Service Unavailable
body: <p>I have installed the hudson/jenkins mylyn connector for eclipse (as mentioned here: <a href="https://stackoverflow.com/a/11543067/863180">https://stackoverflow.com/a/11543067/863180</a>)</p>
  
  <p>I have configured my jenkins, but i always this error: Server validation failed: Unexpected error: Unexpected response from server while logging in: Service Unavailable</p>
  
  <p>This is the complete error: </p>
  
  <pre><code>eclipse.buildId=unknown
  java.version=1.7.0_13
  java.vendor=Oracle Corporation
  BootLoader constants: OS=win32, ARCH=x86_64, WS=win32, NL=en_US
  Framework arguments:  -showlocation -product com.jboss.jbds.product.product
  Command-line arguments:  -os win32 -ws win32 -arch x86_64 -showlocation -product com.jboss.jbds.product.product
  
  Error
  Wed Jul 31 08:39:16 CEST 2013
  Server validation failed: Unexpected error: Unexpected response from server while logging in: Service Unavailable
  
  org.eclipse.core.runtime.CoreException: Unexpected error: Unexpected response from server while logging in: Service Unavailable
      at org.eclipse.mylyn.internal.hudson.core.HudsonCorePlugin.toCoreException(HudsonCorePlugin.java:61)
      at org.eclipse.mylyn.internal.hudson.core.HudsonServerBehaviour.validate(HudsonServerBehaviour.java:908)
      at org.eclipse.mylyn.builds.internal.core.BuildServer.validate(BuildServer.java:369)
      at org.eclipse.mylyn.builds.ui.spi.BuildServerPart$Validator.run(BuildServerPart.java:114)
      at org.eclipse.mylyn.commons.repositories.ui.RepositoryLocationPart$2.run(RepositoryLocationPart.java:558)
      at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:121)
  Caused by: org.eclipse.mylyn.internal.hudson.core.client.HudsonException: Unexpected response from server while logging in: Service Unavailable
      at org.eclipse.mylyn.internal.hudson.core.client.HudsonOperation.run(HudsonOperation.java:169)
      at org.eclipse.mylyn.internal.hudson.core.client.RestfulHudsonClient.validate(RestfulHudsonClient.java:412)
      at org.eclipse.mylyn.internal.hudson.core.HudsonServerBehaviour.validate(HudsonServerBehaviour.java:902)
      ... 4 more
  Caused by: java.io.IOException: Unexpected response from server while logging in: Service Unavailable
      at org.eclipse.mylyn.internal.hudson.core.client.HudsonOperation.authenticate(HudsonOperation.java:96)
      at org.eclipse.mylyn.commons.repositories.http.core.CommonHttpOperation.executeOnce(CommonHttpOperation.java:114)
      at org.eclipse.mylyn.commons.repositories.http.core.CommonHttpOperation.execute(CommonHttpOperation.java:65)
      at org.eclipse.mylyn.internal.hudson.core.client.RestfulHudsonClient$8.execute(RestfulHudsonClient.java:390)
      at org.eclipse.mylyn.internal.hudson.core.client.RestfulHudsonClient$8.execute(RestfulHudsonClient.java:1)
      at org.eclipse.mylyn.internal.hudson.core.client.HudsonOperation.run(HudsonOperation.java:167)
      ... 6 more
  </code></pre>
  
  <p>What can i do to fix this?</p>