Display issues when connecting to RealVNC Server running on Windows

Follow

In some circumstances, your remote computer running Windows will not display correctly in RealVNC Viewer. The commonly reported issues are:

  • a black or blank screen
  • application windows are white
  • the Start Menu is smaller than expected

The issue is most commonly seen when connecting to a computer with no monitors attached (headless), or a monitor using HDMI/DisplayPort is connected but powered off.

In the above situations, Windows does not correctly report graphical updates to be captured by RealVNC Server using DirectX.

Please find below a list of workarounds that you can use to mitigate this issue:

  1. Change your Power settings on the RealVNC Server computer to never turn off the monitors/displays and that Windows is not set to a "Battery Saver" power mode.
  2. If RealVNC Server is running on a laptop, do not completely close the laptop lid.
  3. If HDR is enabled for a particular monitor, try disabling HDR support in Windows display settings.
  4. Disable DirectX tracking in VNC Server's Options, Troubleshooting section:
    1. On the remote Windows computer, open the RealVNC Server dialog, using the Start Menu or taskbar icon.
    2. Select Options from the hamburger menu at the top right
    3. Select Troubleshooting from the left menu
    4. Disable the checkbox for DirectX and click Apply.
      • This can also be changed:
        • In RealVNC Server's Options, Expert section using the CaptureMethod parameter and setting a value of 1, or;
        • In the Registry under HKLM\Software\RealVNC\vncserver by creating a String value named CaptureMethod and with a value of 1.

          RealVNC Server must be restarted after manually editing the Registry.
  5. Connect an EDID emulator to the VNC Server computer. An example EDID emulator can be seen here.
    Note: RealVNC have not tested this particular emulator and it is only provided as an example.

 

Was this article helpful?
215 out of 557 found this helpful

Comments

7 comments
  • In addition to what is stated in the article, I also found it necessary to make sure Gamestream for Nvidia shield is turned on under the Geforce experience settings menu. If this setting is off, the GPU will not properly utilize DirectX screen capture.

    0
    Comment actions Permalink
  • OPs solutions 1 and 3 didn't help for me, and I don't have an HDMI dummy available. However, I found the following solution which works on my Acer Notebook:

    Make sure that your Laptop lid is opened while you do this!

    "Here are the steps:

    1. Open Device Manager (search it in the Start menu).
    2. In "System devices" find "ACPI lid".
    3. Open "ACPI lid" properties, and go to the "Driver" tab.
    4. Select "Update driver".
    5. Choose "Browse my computer for driver software" and "Let me pick.."
    6. Uncheck "Show compatible hardware".
    7. In "Manufacturer" select "(Standard system devices)", or in Windows 8 and 10, choose Microsoft as the manufacturer - different place, but the hack still works
    8. For model, select "Volume manager".
    9. Restart the system and it works!"

    From: https://superuser.com/a/380038

    EDIT from RealVNC: The steps above are at user's own risk, they have not been tested by RealVNC.

    2
    Comment actions Permalink
  • I have a Dell computer that has this issue. I recommend option 4 and there are some really cool ones that emulate very high resolution monitors.

    But I'm cheap. While 75Ω resistors are optimal, the closest I had was 100Ω. Take three and put them across holes 1-7, 2-6 and 3-5.

    0
    Comment actions Permalink
  • Hi all,

    It is related with Controller of the Display adapter, I changed in: Right clic on My PC, Manage, Device Manager, Right clic under interface, properties, Roll back driver.

    After this change everything came back to normal, and the black screen was fixed.

    Cheers,
    Diego Tapia

    0
    Comment actions Permalink
  • 2023 : If using NVIDA drivers. Gamestream under Nvidia shield is blocking the screen to show display in VNC Viewer. Turn on Gamestream under the Geforce experience settings menu. Remember to add VNC servers executable as a game in the shield settings, in addition you must disable "use directx tracking to capture screen" under VNC servers settings; troubleshooting. After this it will work. Maybe the simplest way would be to remove GeForce Experience from the PC and smile. 

    0
    Comment actions Permalink
  • Used VNC since the 90s up until a couple of years ago, and never knew that it now required headless hardware to work. I've hooked into hundreds of servers, years ago, via VNC, Windows servers as well, but never had an issue until I tried again today (as a backup to RDP issues on Win Servers). Is this a Microsoft thing or a hardware thing? What happened?
    (doesn't this kind of defeat the purpose of VNC? - forcing all machines to have a monitor plugged in? What about datacenters?)

    0
    Comment actions Permalink
  • Dave, I have a couple thoughts. The hardware for some computers require a monitor, which, I agree, kind of defeats the purpose. You can buy many fancy devices that emulate a monitor, but for a computer with a VGA port, a 75Ω resistor from G(reen) signal to Ground works pretty well. You'll find that the aforementioned devices for HDMI do pretty much the same thing. $3-$4 on Amazon, $2-$3 on AliExpress.

    I have also found that I am using mostly command line when I access a server. So I recommend having ssh as a backup.

    0
    Comment actions Permalink

Article is closed for comments.