After upgrading our Citrix XenApp Environment users are unable to launch published APP-V  applications.
Error: "Cannot start unknown application"

The above mentioned sample code is provided to you as is with no representations, warranties or conditions of any kind. You may use, modify and distribute it at your own risk. CITRIX DISCLAIMS ALL WARRANTIES WHATSOEVER, EXPRESS, IMPLIED, WRITTEN, ORAL OR STATUTORY, INCLUDING WITHOUT LIMITATION WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NONINFRINGEMENT. Without limiting the generality of the foregoing, you acknowledge and agree that (a) the sample code may exhibit errors, design flaws or other problems, possibly resulting in loss of data or damage to property; (b) it may not be possible to make the sample code fully functional; and (c) Citrix may, without notice or liability to you, cease to make available the current version and/or any future versions of the sample code. In no event should the code be used to support ultra-hazardous activities, including but not limited to life support or blasting activities. NEITHER CITRIX NOR ITS AFFILIATES OR AGENTS WILL BE LIABLE, UNDER BREACH OF CONTRACT OR ANY OTHER THEORY OF LIABILITY, FOR ANY DAMAGES WHATSOEVER ARISING FROM USE OF THE SAMPLE CODE, INCLUDING WITHOUT LIMITATION DIRECT, SPECIAL, INCIDENTAL, PUNITIVE, CONSEQUENTIAL OR OTHER DAMAGES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Although the copyright in the code belongs to Citrix, any distribution of the sample code should include only your own standard copyright attribution, and not that of Citrix. You agree to indemnify and defend Citrix against any and all claims arising from your use, modification or distribution of the sample code.

To validate correct deliverygroup UID is assigned to ASD:

---

Problem Cause

Delivery group no longer associated with ASD after upgrade.

When you assign an App-v Application to a delivery group the DDC creates a policy Blob.
This ASD (ApplicationStartDetails) Blob contains Appv Application assignments.

To review these blobs run:
PS C:\WINDOWS\system32> Get-BrokerConfigurationSlot
 
PS C:\WINDOWS\system32> Get-BrokerMachineConfiguration
   
 
If assigned to a Delivery group you will see the the delivery group UID present under DesktopGroupUids in the above output.
 
During registration the DDC will determine if an ASD should be sent to a VDA based on their DeliveryGroup Membership
If there is no DesktopGroupUid present the ASD will not be sent.