Remote Desktop Licensing Manager was not able to install the client license key on Windows Server 2022

Question

Hello,

I am trying to install Windows Server 2025 RDS CAL 5 Device on a server running Windows Server 2022. I have received the license key pack ID via Microsoft activation website as well as by calling Microsoft support via telephone (both Key pack IDs are the same). When I enter the key pack ID, I will receive an Error indicating "Remote Desktop Licensing Manager was not able to install the client license key" as shown below.

I have tried all three different connection methods (Automatic Connection, Web browser, and Telephone) but did not succeed. I would appreciate for any advice that can assist me to resolve this issue.

Thanks,

Ebrahim Manesh

Mod moved from Windows Insider

Answer 1

Hello Manesh,

The error you’re encountering when attempting to install Windows Server 2025 RDS CALs on a Windows Server 2022 system is due to a version mismatch. Remote Desktop Services CALs must match the version of the license server they are being installed on. A Windows Server 2022 RDS Licensing Server cannot accept and install Windows Server 2025 CALs. The licensing manager enforces this strictly, which is why you see “Remote Desktop Licensing Manager was not able to install the client license key” regardless of whether you use automatic, web, or telephone activation.

The supported configuration is that the RDS CAL version must be equal to or greater than the version of the license server. For example, Windows Server 2022 CALs can be installed on a 2022 license server, and Windows Server 2019 CALs can be installed on a 2019 license server. Windows Server 2025 CALs require that the license server itself be upgraded to Windows Server 2025. Microsoft does not allow newer CALs to be back‑installed on older license servers.

To resolve this, you have two options. Either upgrade your RDS Licensing Server to Windows Server 2025 so that it can accept the 2025 CALs, or request the correct version of CALs (Windows Server 2022 RDS CALs) from your licensing provider if you intend to keep the license server on 2022. If you already purchased 2025 CALs but your infrastructure is not yet ready to move to Server 2025, you will need to contact Microsoft Volume Licensing Support to adjust the order, as there is no technical workaround to force 2025 CALs onto a 2022 license server.

I hope you've found something useful here. If it helps you get more insight into the issue, it's appreciated to accept the answer. Should you have more questions, feel free to leave a message. Have a nice day!

Domic Vo.

Answer 2

Hi Domic,

Thank you for your answer. I called Microsoft support, received a downgraded Key Pack ID for RDS CAL 2022, and installed it on the server with no issues.

Regards,

Ebrahim Manesh