1. Stop the QuarkXPress Server service (running as Local User).
  2. Navigate to ‘[drive]:\ProgramData\Quark\QuarkXPress Server 8\Preferences’ and move or delete the 'Preferences' folder for QuarkXPress Server.
  3. Right-click the QXPS 8.x shortcut icon and choose Properties.
  4. Click the Compatibility tab.
  5. Click Run this program in compatibility mode for with the default value Windows XP (Service Pack 3).
  6. Restart the QuarkXPress Server service.
  7. Execute a ‘getserverinfo’ request.

If you want to run QuarkXPress Server in application mode after the above changes, make sure you copy the 'QLAClient.properties' file to the local folder for QuarkXPress Server.