Hello,

Try to reinstall Radmin Server, restart system and check!

If you have a monitor on remote side where installed Radmin Server, please check that it plugged in

You should do the following:

If you use Windows 7 on this PC:

1. Check if the latest version of Radmin Server is installed there (it's 3.5.2 for now).

After updating Radmin Server, you need to restart this PC.

If you use Windows 10 /11 on this PC:

1. Check if the latest version of Radmin Server is installed there (it's 3.5.2 for now).

After updating Radmin Server, you need to restart this PC.

2. Check out the latest updates for Windows 10/11.

3. Check if the latest drivers are installed on the video adapter

4. If you use virual machine, try Installation of virtual monitor driver.

5. If it didn't help and there is no a video card with display port \ hdmi

and there is no monitor connected, then try

https://www.amazon.com/Headless-Display-Emulator-Headless-1920x1080-generation/dp/B06XT1Z9TF

6. You can also try Mini DP display emulator dummy plugs:

https://www.amazon.com/FREEGENE-Thunderbolt-Display-Emulator-3840x2160/dp/B0758675CJ

7. Go to the properties of the video adapter. (windows setting - system - display - advanced display settings - display adapter properties, monitor tab, uncheck hide modes that this monitor)

8. Try to change screen resolution.

9. IF HDR was turned on, the desktop. Turning it off can fix the problem.

https://pureinfotech.com/enable-auto-hdr-games-windows-11/

https://support.microsoft.com/en-us/windows/hdr-settings-in-windows-2d767185-38ec-7fdc-6f97-bbc6c5ef24e6

If you want to use HDR, but see black screen, please, check this link:

https://support.microsoft.com/en-us/windows/hdr-settings-in-windows-2d767185-38ec-7fdc-6f97-bbc6c5ef24e6

You can also try this:

1. Open device manager

2. In "System devices" find "ACPI lid"

3. Open "ACPI lid" properties, and go to "Driver" tab.

4. Select "Update driver"

5. Choose "Browse my computer for driver software" and "Let me pick…"

Uncheck "Show compatible hardware"

6. And now...in "Manufacturer" select "(Standard system devices)" and model:

"Volume manager" (yes, "Volume manager")

7. next, next and restart the system.

Create a new account with the same rights in Radmin Server.

To do this, right-click on Radmin Server

Open settings Radmin Server

Click button Permissions

Appears windows Radmin Server Security Mode

Click button Permissions

Click Add User

Add user and password with the same rights

Restart.

Connect with a new user

If it helps, delete old user (before to do this, check rights)

If the above option did not help, then try to disable the Display adapter on Radmin Server Side in Task Manager

If you use two video cards, and one of them is Nvidia, disable temporary Nvidia and select to use integrated for rserver3.exe.

Please, check Microsoft remote assistance (quick assist), returns a black screen or does it work?

Black screen issues with Radmin usually come down to GPU driver/compatibility problems, especially with brand-new cards like the RTX 5090. A few things you could try:

• Make sure you’re on the latest NVIDIA drivers (sometimes early releases for new GPUs don’t play nicely with remote display hooks).

• Check if hardware acceleration can be toggled or limited — some users report better results disabling certain acceleration features in apps or the GPU control panel.

• Try running Radmin in compatibility mode or with admin rights to see if it changes capture behavior.

• As a test, enable the “standard VGA” or Microsoft Basic Display Adapter temporarily — if Radmin works then, it’s almost certainly a driver issue.

Since it works fine on the 5070 and older cards, it looks like the 5090 support is just too new for Radmin’s capture driver. If nothing helps, you might need to reach out to Radmin support to see if an update is planned.