A Microsoft desktop and app virtualization service that runs on Azure. Previously known as Windows Virtual Desktop.
Every time a user at my job gets that message (at least in my experiences), there is usually an update for Remote Desktop(if that is what you are using). I have them open MS Remote Desktop and in the top right, if there is an update, a green mark will show on the 3 dots. I have them click on that and run the update. Once it's finished, they can connect successfully.
Hope this helps.