RQM Exception :AQXSP5007E

Hello ,
could anyone explain me what's the root cause of following exception (sorry,very long):
ERROR com.ibm.rational.test.lm.service - class com.ibm.rational.test.lm.service.spi.ProviderRestService:postSyncAllVirtualMachines AQXSP5007E Encountered an error within the external provider SPI: Item handle must not be null
java.lang.IllegalArgumentException: Item handle must not be null
at com.ibm.team.repository.service.internal.ComponentRepositoryItemService.deleteItem(ComponentRepositoryItemService.java:479)
at com.ibm.rational.test.lm.service.spi.integration.VMToVILinkService.removeLink(VMToVILinkService.java:143)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:79)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:370)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:356)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
at $Proxy611.removeLink(Unknown Source)
at com.ibm.rational.test.lm.service.spi.integration.IntegrationService.deleteUnusedAsset(IntegrationService.java:2843)
at com.ibm.rational.test.lm.service.spi.integration.IntegrationService.syncAllVirtualMachines(IntegrationService.java:2721)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:79)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:370)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:356)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
at $Proxy790.syncAllVirtualMachines(Unknown Source)
at com.ibm.rational.test.lm.service.spi.ProviderRestService.postSyncAllVirtualMachines(ProviderRestService.java:1904)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:79)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:370)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:356)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
at $Proxy807.postSyncAllVirtualMachines(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:79)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at com.ibm.team.repository.servlet.AbstractTeamServerServlet.doModelledRestService(AbstractTeamServerServlet.java:504)
at com.ibm.team.repository.servlet.AbstractTeamServerServlet.handleRequest2(AbstractTeamServerServlet.java:1869)
at com.ibm.team.repository.servlet.AbstractTeamServerServlet.handleRequest(AbstractTeamServerServlet.java:1725)
at com.ibm.team.repository.servlet.AbstractTeamServerServlet.service(AbstractTeamServerServlet.java:1634)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.eclipse.equinox.http.registry.internal.ServletManager$ServletWrapper.service(ServletManager.java:180)
at org.eclipse.equinox.http.servlet.internal.ServletRegistration.handleRequest(ServletRegistration.java:90)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:111)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:75)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.eclipse.equinox.servletbridge.BridgeServlet.service(BridgeServlet.java:120)
at com.ibm.team.repository.server.servletbridge.JazzServlet.service(JazzServlet.java:76)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:172)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:563)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
at org.apache.catalina.authenticator.SingleSignOn.invoke(SingleSignOn.java:420)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:879)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
at java.lang.Thread.run(Thread.java:811)


when RQM imports this Virtual Image definition via Virtual Adapter:

<xml>

<core>

  <server>

    <core>

      <core>running</core>

    </core>

    <server>

    <core>

    <core>

  </server>

  <os>

    <os>

    <core>

  </os>

  <net>

    <net>

  </net>

  <virtualization>

    <virtualization>

      <core>

        <core>SCP.win2k8_64</core>

      </core>

      <core>

        <core>KVM</core>

      </core>

    </virtualization>

    <core>

  </virtualization>

  <os>

    <os>

  </os>