Users may notice that when launching a published application or a published desktop, the session gets stuck on a black screen or a blue screen. 

Below are the possible solutions to address this issue. They can be tested one by one and see if any of them address the issue. 

Solution 1

Add or set the following registry key on the VDA server(s) or the to resolve the issue. 

Caution! Refer to the Disclaimer at the end of this article before using Registry Editor.

Registry Key: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Citrix\Logon
Name: DisableStatus
Type: REG_DWORD
Value: 00000001

Note: This registry entry needs to be created if it doesn't exist already.

Solution 2

On the server hosting the application / desktop, the AppInit_DLLs registry key can either contain the short name (C:\Progra~1\..) or simply the file name which can then be discovered using the PATH variable. When 8dot3 naming is enabled the full file path with the shortname formatting would be valid. But when 8dot3 naming is disabled, short name path would be invalid. In that case, modify the following reg key :

Key Location: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows
Name: AppInit_DLLs
Type: String
Value: mfaphook64.dll

Here we are removing the full path with the shortname format for mfaphook64.dll and replace it with just the name of the dll file. 

Now the published application/desktop session would launch successfully.

If none of the above solutions resolve the problem, collect CDF traces from the client and from the VDA side while reproducing the issue and engage Citrix support for further investigation. For more information on CDF tracing, please refer to Citrix CDFControl Tool .

Note: Make sure to start the Client side and VDA side traces before launching the ICA Session, launch the ICA Session, wait for the problem to be reproduced and stop the traces. 

Problem Cause

• There can be several factors that can result in this issue. A majority of them are related to drive mappings or folder redirections in logon scripts, user profiles and/or GPOs, which point to an incorrect location or experience delays mapping during the logon process.
• This problem can also happen if the AppInit_Dlls reg key is improperly configured. Appinit_DLLs registry key considers space as a delimiter. So, a value C:\Program Files\.. would be invalid (because there is a space between Program and Files). In certain scenarios the 8dot3 naming convention (C:\Progra~1) will be disabled at the OS level and this can result in the AppInit_dll value becoming invalid. 

• Query / Change the settings for short name (8dot3 name) behavior.
• The desktop does not load and only displays a black or blue background after you log on to a computer that is running Windows 7 or Windows Server 2008 R2.
• Unable to Connect to XenDesktop Virtual Desktop Agent on Vista or Windows 7 with WDDM Driver