title: PalletOps-VirtualBox Cannot unregister the machine
body: <p>I am struggling to get PalletOps work with vbox 4.3. Their chemistry before was fine.</p>
  
  <p>When I do pallet up scripts, I get following <strong>Cannot unregister the machine</strong> error, </p>
  
  <pre><code>$ VBoxManage setproperty websrvauthlibrary null
  $ vboxwebsrv -t0
  $ lein pallet up --roles local --phases update-shared,install,configure,build,deploy 
  
  Sep 06, 2014 6:31:42 PM clojure.tools.logging$eval378$fn__379 invoke
  INFO: Connecting to VirtualBox via Web Services
  Sep 06, 2014 6:31:58 PM clojure.tools.logging$eval378$fn__379 invoke
  INFO: No :default-bridged-interface defined. Will chose from these options: eth0
  Sep 06, 2014 6:32:13 PM clojure.tools.logging$eval378$fn__379 invoke
  INFO: create-machine: Creating machine local-web-0-0 in /home/prayagupd/.vmfest/nodes/vmfest/local-web-0-0/local-web-0-0.vbox,  overwriting previous contents
  
  ...
  
  Sep 06, 2014 6:32:15 PM clojure.tools.logging$eval378$fn__379 invoke
  WARNING: ensure-image-is-registered: /home/prayagupd/.vmfest/models/vmfest-ubuntu-12.04.vdi is not mutable.
  Sep 06, 2014 6:39:41 PM clojure.tools.logging$eval378$fn__379 invoke
  INFO: unregister: unregistering machine with name local-storm-0-0 with cleanup DetachAllReturnHardDisksOnly
  Sep 06, 2014 6:39:42 PM clojure.tools.logging$eval378$fn__379 invoke
  INFO: unregister: unregistering machine with name local-web-0-0 with cleanup DetachAllReturnHardDisksOnly
  Sep 06, 2014 6:39:42 PM clojure.tools.logging$eval378$fn__379 invoke
  INFO: unregister: unregistering machine with name local-userflood-0-0 with cleanup DetachAllReturnHardDisksOnly
  Sep 06, 2014 6:39:47 PM clojure.tools.logging$eval378$fn__379 invoke
  SEVERE: Cannot parse the error since the object is unavailable java.lang.IllegalArgumentException: No matching field found: getIntefaceID for class org.virtualbox_4_3.IVirtualBoxErrorInfo
  Sep 06, 2014 6:39:47 PM clojure.tools.logging$eval378$fn__379 invoke
  SEVERE: Cannot parse the error since the object is unavailable java.lang.IllegalArgumentException: No matching field found: getIntefaceID for class org.virtualbox_4_3.IVirtualBoxErrorInfo
  Sep 06, 2014 6:39:47 PM clojure.tools.logging$eval378$fn__379 invoke
  SEVERE: Cannot parse the error since the object is unavailable java.lang.IllegalArgumentException: No matching field found: getIntefaceID for class org.virtualbox_4_3.IVirtualBoxErrorInfo
  Sep 06, 2014 6:39:47 PM clojure.tools.logging$eval378$fn__379 invoke
  SEVERE: conditions: This VBoxException does not have an error type {}
  Sep 06, 2014 6:39:47 PM clojure.tools.logging$eval378$fn__379 invoke
  SEVERE: conditions: This VBoxException does not have an error type {}
  Sep 06, 2014 6:39:47 PM clojure.tools.logging$eval378$fn__379 invoke
  SEVERE: conditions: This VBoxException does not have an error type {}
  Sep 06, 2014 6:39:47 PM clojure.tools.logging$eval378$fn__379 invoke
  SEVERE: Cannot parse the error since the object is unavailable java.lang.IllegalArgumentException: No matching field found: getIntefaceID for class org.virtualbox_4_3.IVirtualBoxErrorInfo
  Sep 06, 2014 6:39:47 PM clojure.tools.logging$eval378$fn__379 invoke
  SEVERE: Cannot parse the error since the object is unavailable java.lang.IllegalArgumentException: No matching field found: getIntefaceID for class org.virtualbox_4_3.IVirtualBoxErrorInfo
  Sep 06, 2014 6:39:47 PM clojure.tools.logging$eval378$fn__379 invoke
  SEVERE: Cannot parse the error since the object is unavailable java.lang.IllegalArgumentException: No matching field found: getIntefaceID for class org.virtualbox_4_3.IVirtualBoxErrorInfo
  Sep 06, 2014 6:39:47 PM clojure.tools.logging$eval378$fn__379 invoke
  WARNING: Processing exception class clojure.lang.ExceptionInfo as a java.lang.Exception. Cause clojure.lang.ExceptionInfo: throw+: {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;} {:object {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;}, :environment {exception #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;, optional-keys nil, message "An exception occurred.", full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)"}}
  Sep 06, 2014 6:39:47 PM clojure.tools.logging$eval378$fn__379 invoke
  WARNING: Processing exception class clojure.lang.ExceptionInfo as a java.lang.Exception. Cause clojure.lang.ExceptionInfo: throw+: {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-web-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-web-0-0' while it is locked (0x80bb0007)&gt;} {:object {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-web-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-web-0-0' while it is locked (0x80bb0007)&gt;}, :environment {exception #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-web-0-0' while it is locked (0x80bb0007)&gt;, optional-keys nil, message "An exception occurred.", full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-web-0-0' while it is locked (0x80bb0007)"}}
  Sep 06, 2014 6:39:47 PM clojure.tools.logging$eval378$fn__379 invoke
  WARNING: Processing exception class clojure.lang.ExceptionInfo as a java.lang.Exception. Cause clojure.lang.ExceptionInfo: throw+: {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;} {:object {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;}, :environment {exception #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;, optional-keys nil, message "An exception occurred.", full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)"}}
  Sep 06, 2014 6:39:47 PM clojure.tools.logging$eval378$fn__379 invoke
  SEVERE: Start of node exception: throw+: {:message "An error occurred", :log-level :error, :type :exception, :original-message "throw+: {:full-message \"An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)\", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;}", :full-message "An error occurred: throw+: {:full-message \"An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)\", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;}", :cause #&lt;ExceptionInfo clojure.lang.ExceptionInfo: throw+: {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;} {:object {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;}, :environment {exception #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;, optional-keys nil, message "An exception occurred.", full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)"}}&gt;}
  clojure.lang.ExceptionInfo: throw+: {:message "An error occurred", :log-level :error, :type :exception, :original-message "throw+: {:full-message \"An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)\", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;}", :full-message "An error occurred: throw+: {:full-message \"An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)\", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;}", :cause #&lt;ExceptionInfo clojure.lang.ExceptionInfo: throw+: {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;} {:object {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;}, :environment {exception #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;, optional-keys nil, message "An exception occurred.", full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)"}}&gt;} {:object {:message "An error occurred", :log-level :error, :type :exception, :original-message "throw+: {:full-message \"An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)\", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;}", :full-message "An error occurred: throw+: {:full-message \"An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)\", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;}", :cause #&lt;ExceptionInfo clojure.lang.ExceptionInfo: throw+: {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;} {:object {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;}, :environment {exception #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;, optional-keys nil, message "An exception occurred.", full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)"}}&gt;}, :environment {exception #&lt;ExceptionInfo clojure.lang.ExceptionInfo: throw+: {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;} {:object {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;}, :environment {exception #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;, optional-keys nil, message "An exception occurred.", full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)"}}&gt;, optional-keys {:log-level :error, :message "An error occurred"}, message "An error occurred", full-message "An error occurred: throw+: {:full-message \"An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)\", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-userflood-0-0' while it is locked (0x80bb0007)&gt;}"}}
      at vmfest.virtualbox.conditions$wrap_exception.invoke(conditions.clj:132)
      at vmfest.manager$destroy.doInvoke(manager.clj:558)
      at clojure.lang.RestFn.invoke(RestFn.java:410)
      at pallet.compute.vmfest.service$create_node.invoke(service.clj:433)
      at pallet.compute.vmfest.service$parallel_create_nodes$iter__16850__16854$fn__16855$fn__16860.invoke(service.clj:555)
      at clojure.core$binding_conveyor_fn$fn__3989.invoke(core.clj:1819)
      at clojure.lang.AFn.call(AFn.java:18)
      at java.util.concurrent.FutureTask.run(FutureTask.java:262)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
      at java.lang.Thread.run(Thread.java:744)
  
  ...
  
  Sep 06, 2014 6:39:47 PM clojure.tools.logging$eval378$fn__379 invoke
  SEVERE: Start of node exception: throw+: {:message "An error occurred", :log-level :error, :type :exception, :original-message "throw+: {:full-message \"An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)\", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;}", :full-message "An error occurred: throw+: {:full-message \"An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)\", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;}", :cause #&lt;ExceptionInfo clojure.lang.ExceptionInfo: throw+: {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;} {:object {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;}, :environment {exception #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;, optional-keys nil, message "An exception occurred.", full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)"}}&gt;}
  clojure.lang.ExceptionInfo: throw+: {:message "An error occurred", :log-level :error, :type :exception, :original-message "throw+: {:full-message \"An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)\", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;}", :full-message "An error occurred: throw+: {:full-message \"An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)\", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;}", :cause #&lt;ExceptionInfo clojure.lang.ExceptionInfo: throw+: {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;} {:object {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;}, :environment {exception #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;, optional-keys nil, message "An exception occurred.", full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)"}}&gt;} {:object {:message "An error occurred", :log-level :error, :type :exception, :original-message "throw+: {:full-message \"An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)\", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;}", :full-message "An error occurred: throw+: {:full-message \"An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)\", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;}", :cause #&lt;ExceptionInfo clojure.lang.ExceptionInfo: throw+: {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;} {:object {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;}, :environment {exception #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;, optional-keys nil, message "An exception occurred.", full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)"}}&gt;}, :environment {exception #&lt;ExceptionInfo clojure.lang.ExceptionInfo: throw+: {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;} {:object {:full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;}, :environment {exception #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;, optional-keys nil, message "An exception occurred.", full-message "An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)"}}&gt;, optional-keys {:log-level :error, :message "An error occurred"}, message "An error occurred", full-message "An error occurred: throw+: {:full-message \"An exception occurred.: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)\", :cause #&lt;VBoxException org.virtualbox_4_3.VBoxException: VirtualBox error: rc=0x80bb0007 Cannot unregister the machine 'local-storm-0-0' while it is locked (0x80bb0007)&gt;}"}}
      at vmfest.virtualbox.conditions$wrap_exception.invoke(conditions.clj:132)
      at vmfest.manager$destroy.doInvoke(manager.clj:558)
      at clojure.lang.RestFn.invoke(RestFn.java:410)
      at pallet.compute.vmfest.service$create_node.invoke(service.clj:433)
      at pallet.compute.vmfest.service$parallel_create_nodes$iter__16850__16854$fn__16855$fn__16860.invoke(service.clj:555)
      at clojure.core$binding_conveyor_fn$fn__3989.invoke(core.clj:1819)
      at clojure.lang.AFn.call(AFn.java:18)
      at java.util.concurrent.FutureTask.run(FutureTask.java:262)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
      at java.lang.Thread.run(Thread.java:744)
  </code></pre>
  
  <p>After the script fails, following vbox are running, </p>
  
  <pre><code>$ ps aux | grep -i virtualbox
  1000     17971  0.4  0.1 752612  6052 pts/0    Sl+  18:30   0:06 /usr/lib/virtualbox/vboxwebsrv -t0
  1000     17983  0.2  0.0 123380  3596 ?        S    18:30   0:04 /usr/lib/virtualbox/VBoxXPCOMIPCD
  1000     17991  0.6  0.2 832724  9640 ?        Sl   18:30   0:10 /usr/lib/virtualbox/VBoxSVC --auto-shutdown
  1000     19968  2.3  6.2 1428520 230384 ?      Sl   18:32   0:35 /usr/lib/virtualbox/VBoxHeadless --comment local-userflood-0-0 --startvm e8dc9e3c-0d77-44e6-a7c4-c6eefd08f05d --vrde config
  1000     19969  2.2  6.1 1428520 229360 ?      Sl   18:32   0:34 /usr/lib/virtualbox/VBoxHeadless --comment local-storm-0-0 --startvm bab660b9-77dc-44cd-88dc-3bb8651bbed5 --vrde config
  1000     19987  2.3  6.2 1432616 233616 ?      Sl   18:32   0:35 /usr/lib/virtualbox/VBoxHeadless --comment local-web-0-0 --startvm 45e738ef-afc6-4e64-a3d6-37194d7ce40e --vrde config
  1000     25331  1.4  1.3 1224236 49928 ?       Sl   18:53   0:03 /usr/lib/virtualbox/VirtualBox
  1000     26137  0.0  0.0  13644   964 pts/1    R+   18:57   0:00 grep --color=auto -i virtualbox
  </code></pre>
  
  <p>I killed the <code>VBoxHeadless</code> processes and tried the <code>lein pallet</code> script. Still same error.</p>
  
  <p><a href="https://stackoverflow.com/a/13782850/432903">I tried if fresh installation could work, but in vain.</a></p>
  
  <pre><code>## 1. Close Virtualbox if running
  ## 2. 
  sudo apt-get remove virtualbox-\*
  sudo apt-get purge virtualbox-\*
  
  ## 3. 
  rm -r ~/.VirtualBox &amp;&amp; rm - r ~/VirtualBox\ VMs/. ## If you're not sure, back them up to a safe place.
  
  ## 4. 
  sudo reboot
  
  ##5. Reinstall virtualbox.
  sudo dpkg --install /packup/repo.softwares/virtualbox-4.3_4.3.12-93733~Ubuntu~raring_amd64.deb
  </code></pre>