We had the same problem here. What happened was, that we set up a new VM for Version 11 and left the Version 10 VM online. Both Machiens were in the same subnet. So the QVS11 found that the license is already in use on the QVS10. We simply shutdown the QVS10 and restartet the services. After we found the QVS11 working, we deleted the old QVS10 VM.