A black screen is shown when shadowing a user session in Director, and a prompt of admin right is required appears on VDA.

VDA Side：



Director side：

Citrix is not responsible for and does not endorse or accept any responsibility for the contents or your use of these third party Web sites. Citrix is providing these links to you only as a convenience, and the inclusion of any link does not imply endorsement by Citrix of the linked Web site. It is your responsibility to take precautions to ensure that whatever Web site you use is free of viruses or other harmful items.

1. Added AD policies from Computer Configuration\Windows Settings\Security Settings\Local Policies\Security Options

• User Account Control: Allow UIAccess applications to prompt for elevation without using the secure desktop -> Enabled
• User Account Control: Switch to the secure desktop when prompting for elevation -> Disabled

---

Problem Cause

We use Microsoft remote assistance function to shadow user session in director . And it is the default behavior by Microsoft remote assistant function. 

The user would be presented with a normal UAC dialog box with a prompt to put credentials in, but the tech helping them just saw a big black box. This was happening because UAC prompts don’t quite go to the user’s desktop, but rather to something called Secure Desktop. To quote Microsoft:

The Secure Desktop’s primary difference from the User Desktop is that only trusted processes running as SYSTEM are allowed to run here (i.e. nothing running as the User’s privilege level) and the path to get to the Secure Desktop from the User Desktop must also be trusted through the entire chain.”

https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-R2-and-2012/jj852245(v=ws.11)?redirectedfrom=MSDN