Desktop background switched to black with RDM

Hello,

In which RDM version do you see this behaviour? Could you please verify the Experience tab from one of the affected RDP sessions?

Regards,
Min

Version is 2025.2.26.0

This is what I have, but know that this did not change, at least done by me, since I have RDM years ago. This also happens with Windows Server 2022 and 2025 so far, not with previous versions.
Could be a change of behaviour of RDM?

Hello

This could be a change in both the RDP protocol and RDM itself.

If you uncheck "Detect network automatically" and explicitly check "Desktop background", does it work as expected?

Thanks and kind regards,

Sorry the late reply. Was testing the changes but it seems it does not resolve the issue. Still testing, as I'm not 100% sure (background might have been removed from a previous connection).

Hello

The options in the experience tab control the desktop background. If you check "detect network automatically", the protocol will look at the connection speed and configure these settings itself (possibly disabling the desktop background). If you uncheck that feature, you can control it directly yourself. But please note that there are other reasons the desktop background might not be displayed even if you explicitly enable it: for example, there is a GPO that forces removal of the background in all RDP sessions.

You should try and isolate if this is a problem with RDP in general, outside of RDM. The easiest way to do that is to connect directly using Microsoft Remote Desktop Connection (mstsc.exe), choosing a high connection speed in the "Experience" tab or otherwise customizing the settings to allow the desktop background. What are the results?

Thanks and kind regards,

Windows RDP client does not show that behaviour, that's why I'm asking here. RDM until some time ago either. Could be a recent update (last months) on RDM or, as you say, some Windows recent change under the hood for Server 2022/2025.

There is no GPO for handling that on the servers, and this happens in all servers of that version with RDM.

Remember, we don't have desktop background (wallpaper) but solid colours. What we see is that the grey colour is turned to black. I do not know if that is the behaviour for low speed connections.

I tried low bandwidth, high and auto-detect with RDP Client and in all cases the proper desktop background colour is shown (grey).

Will continue testing configurations in RDM regarding experience.

Hello

Ok, I understand. As a next step: what about when you open the connection using mstsc, but from RDM? So - right-click, "Open with parameters" > "Open (external)". Do you get the grey background in this case?

Thanks and kind regards,

Apologies for my delayed response, but yes, it works as expected if I use RDC even inside RDM.

Hello

Ok, I've been back over this thread, taken a look at the RDM internals and tried some tests myself and I still don't reproduce the problem nor can I explain it right now.

Let's try to rule out the Microsoft RDP ActiveX control versus a general problem with RDM.

As a test, please take one session where you're having the problem and in the "Advanced" tab change the "RDP Version" from "Latest" to "FreeRDP (Latest)". Ensure that you're forcing the background by configuring "Experience" settings explicitly: "Detect Network Automatically" should be unchecked and ensure that "Desktop Background" is allowed.

Finally, be sure to evaluate by ensuring a desktop background is set in the remote session, then logging off and reconnecting. In my testing I've noticed that if the client wants to change the background (by removing it or otherwise) at connection time, it may not take effect if the session is already logged in on the remote.

Let me know what you find, and thanks for your patience

Kind regards,

I will be testing what you point out, but be aware there is no background, just a background color that is changed to black by RDM when Windows Server is > 2022. This does not happen with Windows 10/11 and Server 2012/2016/2019. I agree that it is quite a strange thing, and is not always verifiable. For example, if I change the background to let's say red, and relogin in the following minutes I get the proper background. It is after hours/days that when I log in, the background is switched to black.

It is strange, not more people are experiencing this. :/

Hello again

Yes, the issue is very strange. I understand that it's a solid colour and not a wallpaper but honestly, I don't know if these cases are handled differently in Windows (where I think a colour other than black is still a "wallpaper", not sure).

I do wonder, if this is a graphics/decode issue rather than an experience one. RDP supports many different codecs, and modern Windows server obviously has a strong preference for modern codecs like AVC. Windows RDP servers are smart enough to send different pieces of the screen over whatever the most optimized codec for that region is (for example, text is better encoded in a different way than a video).

Unfortunately forcing particular codecs to isolate that theory is quite troublesome. RDP tries to control this itself as much as possible, and you can only configure preferences by GPO.

I wonder, if you connect by mstsc.exe and then RDM to the same server and we compare the event viewer log entries here (on the server)

Microsoft-Windows-RemoteDesktopServices-RdpCoreTS
Microsoft-Windows-TerminalServices-ClientActiveXCore
Microsoft-Windows-RemoteDesktopServices-RdpGraphics

If we see a difference in the negotiation of the two sessions?

Thanks and kind regards,

Today, I'm unable to reproduce it to be able to compare the logs.

There is only Microsoft-Windows-RemoteDesktopServices-RdpCoreTS in the server, but it seems confusing (many lines per connection and mixed with disconnections).

Will try it again when I was able to reproduce it.

NOTE: the RDM version was recently updated in the machine I was trying to reproduce it. Running 2026.2.7.0 now.