Hyper-V Enhanced Session Mode stops working and is only fixed by rebooting the guest operating system

Peter Holly 76 Reputation points
2022-07-18T21:24:47.257+00:00

I have a problem where enhanced session mode periodically stops working. Most of the time I am able to connect to my VMs using the enhanced session. Sometimes I will lose the ability to connect with an enhanced session. This happens every couple of days. When this happens I am still able to connect to the VM using either a standard session or by using remote desktop. The only workaround I have found is to reboot the VM. I have tried disabling and then re-enabling the network adapters in both the VM and the host machine, changing the network type on the VM to private instead of public and stopping and restarting the Hyper-V service on the host machine.

The host machine is running Windows 10 Enterprise 21H2. This happens on two different VMs, one is running Windows 10 Enterprise LTSC 21H2 and the other is running Windows 10 Enterprise LTSC 1809. I am trying to connect to the VMs from the same machine and windows instance that is hosting the VMs. I think it happens after a network change on the host machine, for example when changing from ethernet to wifi or when connecting to a VPN on the host machine. It might also happen when the host machine goes into sleep mode.

What is the underlying cause of this issue? Are there other workarounds that don't require rebooting either the VMs or the host?

Windows 10
Windows 10
A Microsoft operating system that runs on personal computers and tablets.
10,165 questions
Hyper-V
Hyper-V
A Windows technology providing a hypervisor-based virtualization solution enabling customers to consolidate workloads onto a single server.
2,462 questions
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  1. Xu Gu (Shanghai Wicresoft Co,.Ltd.) 501 Reputation points Microsoft Vendor
    2022-07-29T08:40:12.817+00:00

    Hello,

    For your situation, my analysis is as follows:

    1. When we use the enhanced session mode, when connecting to the activated virtual machine, a confirmation prompt for the display resolution of the enhanced mode session will be prompted, and you can enter the virtual machine by connecting directly.
    2. The use of enhanced session mode does not require network support, so it has nothing to do with the network.
    3. Switching back to standard mode to view the current system status sometimes prompts "The task you are trying to perform cannot be completed because Remote Desktop Services is currently busy. Please try again in a few minutes. Other users should still be able to log in." Not sure about you Will this happen.
    4. The appearance of the above prompt means that there are multiple concurrent logins in the current system, and these user sessions are active. After repeated testing, it was found that even if you have logged in to the desktop in the enhanced session mode, when you switch back to the standard mode, you will return to Log in to the interface and ask to log in again.
    5. When switching from standard mode to enhanced session mode, it will automatically use the current account to submit automatic login. When the current virtual machine does not have a user password set, a new user login session will be automatically submitted when using VMConnect to connect. At this time, the login session will conflict with the logged in user session in standard mode, because there is no one. Therefore, the above-mentioned failure problem occurs due to the monitoring and processing mechanism.
    6. We know that RDP does not accept login requests with an empty account and password. Obviously, when VMConnect uses the enhanced session mode to connect to a virtual machine with an empty system account and password, it will submit a seemingly non-compliant login request to bypass the The inspection of the RDP protocol specification will eventually lead to this failure. However, if the current account does not have RDP permissions, such as belonging to the Users group, it will be blocked when connecting using enhanced session mode.
    7. I hope my return can help you.

    Best Regards,
    Xu Gu