Receiving "Couldn't connect" for all previously configured connections

Question

This morning, it looks like all previously configured connections to machines I had are throwing the following error:
"Your session ended because the remote PC sent unexpected server authentication certificate. Ask your admin or tech support for help.

Error code: 0x907
Extended error code: 0x0"

I was able to connect with these machines yesterday without issue.

It looks like I received an update and am now running version 10.2.1524.0

Any ideas how to resolve?

Answer 1

Found the issue & fix/workaround:

Version 10.2.1534 of the Microsoft Remote Desktop (WinRT) app refuses to accept Remote Desktop Authentication (1.3.6.1.4.1.311.54.1.2) certificates, but will accept Server Authentication (1.3.6.1.5.5.7.3.1) certs.

Obviously Microsoft need to fix this as RDAuth certs are perfectly valid & shouldn't be refused, but for now re-issuing/switching to Server Auth certs works.

FYI @Travis Dallegge , @Joey Homicide

Answer 2

Hi,

1. Could you please confirm if the OS version of client computer you are running?
2. Have you tried to re-fill in the connection settings as a test?
3. Which version of RDC you are using? RDC for mac, andriod others?
   https://learn.microsoft.com/en-us/windows-server/remote/remote-desktop-services/clients/remote-desktop-clients

Looking forward to your update.

Thanks,
Jenny

Answer 3

Hi,
Thanks for the update and details.
1.Kindly confirm what update or other changes you 've made before the issue occurrence.

2.From the error message, it indicated the problem was related to certificate used in remote connection.
Is there any icon you could click to view the certificate when the error message prompted?

3.Is it possible to check if any settings have been changed on the target computer or server?

4.Instead of remoting from windows store app but type in mstsc by right clicking run button from start menu.
After then configure the user account, remote computer or Gateway if any and verify if the remote connection would work.

If not working, click save as to get a .rdp file and navigate to authentication level:i:value with notepad and change it to 0:

• 0: If server authentication fails, connect to the computer without warning (Connect and don't warn me)
  Note: this will reduce the security level of remote connection.
  https://learn.microsoft.com/en-us/windows-server/remote/remote-desktop-services/clients/rdp-files

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Thanks,
Jenny

Answer 4

Just to keep the conversation going. An end user came to me with the above screenshot of the error when using the App Store version. It works for now after a reboot of the target machine

Answer 5

I too just started having this issue... It happens on all of my servers (35 in total) except 2 domain controllers running server core.
All of these servers could previously be connected to until my Remote Desktop client updated to the 10.2.1534.0 version. I have tried this from multiple computers, here's what I've come up with:
As soon as I update the computers to Microsoft Remote Desktop client version 10.2.15340.0 it breaks. At login we get the following error:

However, I have computers that haven't updated to the 10.2.15340.0 version, and they still connect just fine. Also on the computers that have the updated version, on the microsoft store there is the Remote Desktop Preview, I can install that, and it seems to work fine. It appears it is version 10.1.1215.0 of the app... so it's an earlier build.
Also I have no issues connecting to any of the servers using the oldschool native Remote Desktop Connection application (mstsc.exe).

In trying to resolve this issue, I have tried deleting an servers remote desktop certificate and had it recreate it, but that had no effect.