System stops responding when using Citrix Virtual Apps and Desktops

This article helps resolve an issue in which the system stops responding when using Citrix Virtual Apps and Desktops to access a terminal server.

When you use Citrix Virtual Apps and Desktops to access a terminal server, the system may stop responding when you try to sign in, sign out, or shut down the server. This issue is triggered by a deadlock in Local Session Manager (LSM) and Remote Desktop Services (termsvcs.exe).

This issue occurs because Citrix Virtual Apps and Desktops use a Windows Terminal Server (WTS) API when handling a remote desktop request. If a terminal server or remote desktop server component is handling an incoming remote desktop request, it can't make direct or indirect blocking calls to remote desktop services (such as IWTS* or IWRDs APIs).

If you encounter this issue, make sure you have the Citrix components fully patched. If you still encounter this issue, follow up with Citrix for additional support.

Note

To avoid a possible deadlock when calling any methods on this interface, don't make any function or method calls that will directly or indirectly result in a Remote Desktop Services API being called. If you need to make an outbound call, start a new thread and make the outbound call from the new thread.

For more information, see the following articles:

Third-party information disclaimer

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.