We have recently published an article about an error that you might receive after you have decided to try the new Windows Admin Center. There’s one more issue that might bother you and we’ll provide a simple fix for it.
Once you try to connect to Windows Servers 2012, 2012R2 or older you might receive the following error message:
Connection error – ResetRunspaceState is not supported on the server. The server must be running Windows Powershell 5.0 or greater.
If you didn’t bother to check the Install guidelines you might have missed the information which says that Windows Admin Center requires PowerShell features that are not included in Windows Server 2012 and 2012 R2. If you will manage these with Windows Admin Center, you will need to install the Windows Management Framework (WMF) version 5.1 or higher on those servers. This includes older unsupported Server versions if you still use those in your environment.
Install packages can be downloaded from here:
Install and configure WMF 5.1 – PowerShell | Microsoft Docs
Once downloaded, installation is automatic and pretty straight forward but it will require a server restart so keep that in mind.
Hope this helps!