I have requested to stop two virtual applications from the 'Virtual Infrastructure' panel, and the second one reported this error. But then I tried to stop the application again and it worked.

achine 7b865737-83ed-4571-80ad-7365c24a96c7
RECEIVED MESSAGE: Severity[INFO], Event[VAPP_POWEROFF], Component[VIRTUAL_APPLIANCE], Timestamp[1256241879527], Description[], User[admin]
22:04:50.565 [pool-3-thread-12] INFO c.a.v.v.i.VirtualapplianceresourceDeployerPremium - An error was occurred in a virtual machine operation Virtual appliance can not be updated, machine eefcb389-e68a-4cbf-ba1c-a12e71f04182
22:04:51.926 ERROR com.abiquo.util.AbiCloudError - Database error: Cannot shutdown the virtual appliance.[Error code:ABI-S008 Timestamp:1256241891]. Database error:

Unable to shutdown the virtual appliance.
Error Code: ABI-S008
Error ID: 1256241891.
com.sun.ws.management.client.exceptions.FaultException: SOAP Fault: The service cannot comply with the request due to internal processing errors.
     Actor:
      Code: env:Receiver
  Subcodes: wsman:InternalError
    Detail: com.abiquo.virtualfactory.exception.VirtualMachineException: Virtual appliance can not be updated, machine eefcb389-e68a-4cbf-ba1c-a12e71f04182
            VirtualapplianceresourceDeployer:583VirtualapplianceresourceDeployerPremium:124VirtualapplianceresourceHandler:152virtualapplianceresource_Handler:127NativeMethodAccessorImpl:-2NativeMethodAccessorImpl:39DelegatingMethodAccessorImpl:25Method:597ReflectiveRequestDispatcher:109ReflectiveRequestDispatcher:1WSManAgent:115FutureTask:303FutureTask:138Executors:441FutureTask:303FutureTask:138ThreadPoolExecutor:886ThreadPoolExecutor:908Thread:619

at com.sun.ws.management.client.impl.TransferableResourceImpl.put(TransferableResourceImpl.java:385) [wiseman-1.6.jar:na]
at com.sun.ws.management.client.impl.TransferableResourceImpl.put(TransferableResourceImpl.java:299) [wiseman-1.6.jar:na]
at com.abiquo.abiserver.abicloudws.VirtualApplianceWS.changeState(VirtualApplianceWS.java:220) [VirtualApplianceWS.class:na]
at com.abiquo.abiserver.abicloudws.VirtualApplianceWS.shutdownVirtualAppliance(VirtualApplianceWS.java:256) [VirtualApplianceWS.class:na]
at com.abiquo.abiserver.commands.VirtualApplianceCommand.shutdownVirtualAppliance(VirtualApplianceCommand.java:1281) [VirtualApplianceCommand.class:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [na:1.6.0_15]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) [na:1.6.0_15]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) [na:1.6.0_15]
at java.lang.reflect.Method.invoke(Method.java:597) [na:1.6.0_15]
at com.abiquo.abiserver.commands.BasicCommand.onExecute(BasicCommand.java:368) [BasicCommand.class:na]
at com.abiquo.abiserver.commands.BasicCommand.execute(BasicCommand.java:209) [BasicCommand.class:na]
at com.abiquo.abiserver.commands.BasicCommand.execute(BasicCommand.java:252) [BasicCommand.class:na]
at com.abiquo.abiserver.services.flex.NonBlockingService.shutdownVirtualAppliance(NonBlockingService.java:185) [NonBlockingService.class:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [na:1.6.0_15]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) [na:1.6.0_15]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) [na:1.6.0_15]
at java.lang.reflect.Method.invoke(Method.java:597) [na:1.6.0_15]
at flex.messaging.services.remoting.adapters.JavaAdapter.invoke(JavaAdapter.java:406) [flex-messaging-remoting-3.0.jar:3.0.0.544]
at flex.messaging.services.RemotingService.serviceMessage(RemotingService.java:183) [flex-messaging-remoting-3.0.jar:3.0.0.544]
at flex.messaging.MessageBroker.routeMessageToService(MessageBroker.java:1417) [flex-messaging-core-3.0.jar:3.0.0.544]
at flex.messaging.endpoints.AbstractEndpoint.serviceMessage(AbstractEndpoint.java:878) [flex-messaging-core-3.0.jar:3.0.0.544]
at flex.messaging.endpoints.amf.MessageBrokerFilter.invoke(MessageBrokerFilter.java:121) [flex-messaging-core-3.0.jar:3.0.0.544]
at flex.messaging.endpoints.amf.LegacyFilter.invoke(LegacyFilter.java:158) [flex-messaging-core-3.0.jar:3.0.0.544]
at flex.messaging.endpoints.amf.SessionFilter.invoke(SessionFilter.java:49) [flex-messaging-core-3.0.jar:3.0.0.544]
at flex.messaging.endpoints.amf.BatchProcessFilter.invoke(BatchProcessFilter.java:67) [flex-messaging-core-3.0.jar:3.0.0.544]
at flex.messaging.endpoints.amf.SerializationFilter.invoke(SerializationFilter.java:146) [flex-messaging-core-3.0.jar:3.0.0.544]
at flex.messaging.endpoints.BaseHTTPEndpoint.service(BaseHTTPEndpoint.java:274) [flex-messaging-core-3.0.jar:3.0.0.544]
at flex.messaging.MessageBrokerServlet.service(MessageBrokerServlet.java:377) [flex-messaging-core-3.0.jar:3.0.0.544]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) [servlet-api.jar:na]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) [catalina.jar:na]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [catalina.jar:na]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) [catalina.jar:na]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) [catalina.jar:na]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128) [catalina.jar:na]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) [catalina.jar:na]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) [catalina.jar:na]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293) [catalina.jar:na]
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849) [tomcat-coyote.jar:na]
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583) [tomcat-coyote.jar:na]
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454) [tomcat-coyote.jar:na]
at java.lang.Thread.run(Thread.java:619) [na:1.6.0_15]
RECEIVED MESSAGE: Severity[CRITICAL], Event[VAPP_POWEROFF], Component[VIRTUAL_APPLIANCE], Timestamp[1256241891938], Description[SOAP Fault: The service cannot comply with the request due to internal processing errors.
     Actor:
      Code: env:Receiver
  Subcodes: wsman:InternalError
    Detail: com.abiquo.virtualfactory.exception.VirtualMachineException: Virtual appliance can not be updated, machine eefcb389-e68a-4cbf-ba1c-a12e71f04182
            VirtualapplianceresourceDeployer:583VirtualapplianceresourceDeployerPremium:124VirtualapplianceresourceHandler:152virtualapplianceresource_Handler:127NativeMethodAccessorImpl:-2NativeMethodAccessorImpl:39DelegatingMethodAccessorImpl:25Method:597ReflectiveRequestDispatcher:109ReflectiveRequestDispatcher:1WSManAgent:115FutureTask:303FutureTask:138Executors:441FutureTask:303FutureTask:138ThreadPoolExecutor:886ThreadPoolExecutor:908Thread:619
], User[admin]