Hey everyone! I'm having a bit of a headache with my Windows 2025 server that's running Exchange SE. When I try to open the Exchange Management shell, I get this error message: "New-PSSession : [exc2025.hosted.exchange-login.net] Connecting to remote server exc2025.domain.tld failed with the following error message : The WinRM client cannot process the request. It cannot determine the content type of the HTTP response from the destination computer. The content type is absent or invalid. For more information, see the about_Remote_Troubleshooting Help topic." The strange part is that when I connect from a Windows 2016 server, it works perfectly. So it seems like the issue is on the client side of the 2025 server. Anyone have any ideas on what might be causing this?
2 Answers
I've seen similar issues linked to KB5066835, which seems to have affected PowerShell remoting and WinRM. Even though it was meant to fix some issues, it seems to have created new problems for certain systems. This fix was related to timeouts after 10 minutes, but you might want to dive into the specifics of that update here: [October 14, 2025—KB5066835](https://support.microsoft.com/en-gb/topic/october-14-2025-kb5066835-os-builds-26200-6899-and-26100-6899-1db237d8-9f3b-4218-9515-3e0a32729685).
It's worth checking out the 'about_Remote_Troubleshooting' documentation. There's a lot of good info in there that might help you pinpoint the problem. You can find it [here](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_remote_troubleshooting). Just remember, the issue might not just be on your end; sometimes server configurations can lead to these errors.
I get that, but I can access the 2025 server from the 2016 server just fine. The issue pops up when I try to connect to localhost from the 2025 server itself.
But I'm specifically trying to start the Exchange management shell on the 2025 server. I can access the Exchange on the 2025 server from other machines without any hitch.