Problem Definition:

After upgrading a Citrix Server to Citrxi Virtual Apps and Desktops 1912 (Desktop Configuration 4.10 and above), certain Windows applications crash, or experience high CPU utilization.

If the application crashed, then the Windows Application Event Viewer has Event ID 1000 logged.

The application .exe process is listed in the General Tab of the event ID details, and the Exception Code listed is 0xc0000005



 The issue is likely related to a Citrix Hooking.


Disable Citrix hooking for the affected process by appending the application's process name to the value of the following registry key.  For example, if the application crashing is Microsoft Excel, the process name is Excel.exe, and registry modification would be as follows:


Value: badapp1.exe;badapp2.exe;excel.exe;

Note: There is a 14 character limit per process name (including the .exe).  So, if the process name (including .exe) is longer than 14 characters, only use the first 14 characters, for example "longbadappprocessname.exe;" would be "longbadapppro;"

Restart the Citrix Server for the change to take effect.

Additional Information:

Citrix API Hooking generally enhances application compatibility in a Citrix environment.  Hooking is enabled by default.  However, if an application has stability issues with hooking enabled, it should be disabled.

Applies To:

Citrix Virtual Apps and Desktops (CVAD) 1912.

Microsoft Windows Server 2012 R2, 2016, and 2019.