An "EnumDisplayDevicesA() failed" error when running 3DMark suggests that Windows 10 cannot properly identify your monitors or that a third-party application has modified how they are set up.

  1. To fix this issue, open Windows Device Manager.

  2. Expand the Monitors section, and find your monitor(s) in the list of devices.

  3. Right-click and choose "uninstall device" for each monitor, then "uninstall driver".
  4. Open the Action menu and choose Scan for hardware changes to detect your monitor(s). They will reappear in the list.

  5. Restart 3DMark, and run the test again.