Application session does not close while no window is open (black screen)

0 users found this article helpful

Symptoms

Application session does not close while no window is open (black screen).

Cause

If there's a 32-bit application running on a 64-bit session host, it is possible that even after closing an application inside Parallels Secure Workspace, the RDP sessions stay active with no visible window open, only a black screen. This is due to a process that prevents the session closing mechanism to see that the application is closed.

Resolution

On the Remote Desktop Services (RDS) host, list the processes for this RDS session.

Most commonly, a print driver process called Print driver host for applications and/or splwow64.exe may be running and prevents Parallels Secure Workspace from recognizing the application is closed. To test if this is the cause, simply kill this process to see of the RDP session will be terminated in Parallels Secure Workspace.

Navigate to the following registry key: [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\Sysprocs]

Create a DWORD value to allow the operating system to automatically and safely terminate this process:
Value name: splwow64.exe
Data type: REG_DWORD 
Base: Hex 
Value data: 0

In very rare occasions, a process such as PrintDisp.exe can cause session hanging.
On Citrix server environments, another known process that causes this behavior is wfshell.exe
If other processes are causing the same issue, also add these process names as keys into the registry.


The value name should always be the .exe name of the application:

Value name: PrintDisp.exe
Data type: REG_DWORD
Base: Hex
Value data: 0

 

If none of the above processes are causing this issue, then to try to find the process that is causing the session to stay open: end processes one by one on the back-end RDS host until one of them causes the session to log off. 

Sources:

Was this article helpful?

Tell us how we can improve it.