XenDesktop 7.15 LTSR CU2 blinking screen and start menu not clickable

[Stefanos Evangelou1709159370]

Hello, 

 

 

I have a XenDesktop 7.15 LTSR CU2 installation with the Citrix workaround applied for UPM for the known case of black screen, i.e. I have uninstalled the CU2 UPM and installed the CU1 UPM. The XenDesktop 7.15 LTSR CU2 VDA servers are running on Windows Server 2016 Standard (build number 10.0.14393). I have applied all optimizations to the VDA by using the Citrix optimizer and the Citrix recommended template for Windows Server 2016. I also have WEM agent installed on the VDA machines. I have attached the version of each installed product. 

 

1) What I have noticed is that when any Citrix users logs on to a Citrix desktop, they see a blinking screen/desktop and they cannot interact with it. I noticed that if I grant a user with domain admin permissions, this issue goes away, so it seems to be permissions related. Have you seen this issue before in this XenApp/XenDesktop configuration? Anything I am missing here?

2) The start menu of the Citrix desktop is not clickable, i.e. the users cannot interact with it, regardless of permissions or other configuration. 

[James Kindon]

Check your upm logs - have seen keys within user profiles cause this behaviour when permissions break - can't recall the extact key but upm logs usually indicate a permission problem and the key name 

[Yuan Bai]

Black screen issue is fixed basing on LTSR7.15CU2. Please try the hotfix on https://support.citrix.com/article/CTX235399.

[Stefanos Evangelou1709159370]

Hello, 

 

The black screen issue is not what I am talking about here. As per https://support.citrix.com/article/CTX235399. : "7.15 LTSR CU2 sessions might launch as a black screen. " The behaviour in my case is a flickering screen of the hosted desktop, even when connecting as admin via RDP session.

 

I confirm that this issue is also occurring with recently released XenDesktop 7.18. 

 

To James Kindon: When you mention permissions on keys, do you refer to registry or other kind of keys?

[Stefanos Evangelou1709159370]

Hello, 

 

After further testing it appears that the root cause of this issue is the Citrix UPM mandatory profile. After disabling the mandatory profile option in the Citrix UPM GPO policy, the issue seems to be resolved. Will need to check again all configuration settings for the mandatory profile but would like also any feedback from the community in case you have come across this behaviour related to the mandatory profile configuration.

[James Kindon]

apologies, i never noticed your reply come through - yes, there are permissions issues on keys within the registry - UPM Log parser should show you which ones

[Ken Z]

Hi everyone

 

if people are still getting flashing desktops and unresponsive Start Menus when using the "Citrix Method" of creating mandatory profiles for UPM, you need to change the permissions on the following registry key in the mandatory\template registry NTUSER.DAT file tat you copied to the network share

 

Software\Microsoft\SystemCertificates\Root\ProtectedRoots

 

Take ownership, then confirm that the "Authenticated Users" group propagates down to this key and values.

 

Regards

 

Ken Z