We updated the VDA’s of a customer to 2407. The update was made in a PVS vDisk and on standalone VDA VM’s. After the update users weren’t able to connect to published apps anymore. The Desktop shows only a grey screen. I found the ctxUVI error (1005) in the eventlog and the corresponding CTX article. But we never touched that regkey with group policies. After reverting back to VDA 2311 everything is working again. Any ideas???

Maybe Antivirus? I remember that there was once an issue with Trend Micro... https://support.citrix.com/s/article/CTX312452-grey-screen-when-launching-the-applications-or-desktops-ctxuvi-event-id-1005-and-1003?language=en_US

Could be AV or GPO.

Were you able to compare the keys to make sure? But typically its AV as something changed and AV is saying nope I don't like it

Also the AV exclusion for ctxgfx.exe changed when upgrading from 1912 to 2112+. Maybe the AV Exclusion has never been updated? 1912: •

%ProgramFiles%\Citrix\System32\ctxgfx.exe

2112+ •

%ProgramFiles%\Citrix\HDX\bin\ctxgfx.exe

https://community.citrix.com/tech-zone/build/tech-papers/antivirus-best-practices/#_=_

@Balint Oberrauch good point

Nice one guys, but I have to disapoint you, I already checked the AV exclusions, we use MS Defender and all exclusions are present.

List everything you done here so we don't waste time guessing what you did, please.

Sorry, Ray… You are right. • I checked AV exclusions • I disabled AV • I checked the regkey and if there is a GPO for that

No worries man.

There was indeed a difference between the AppInit_DDLs regkeys, on the 2407 VDA, the key Multiple Monitor Hook is missing but there is a new key called FullScreenHook. But no difference if I delete the new key and recreate the other one.

sounds like it's still an unresolved issue?

@Matt Nation have you experiencied this too?

Seeing the grey screen issue but with MCS

The issue hasn’t been resolved yet.

I just found this article and asking myself: why is this by design???? https://support.citrix.com/s/article/CTX584160-uviprocessexcludes-registry-setting-disappears-after-citrix-vda-upgrade?language=en_US

Nice, I will try this after we are back from Igel Disrupt in Munich. See you later, Balint 😜, I will donate you a coffee ☕.

Citrix support replied yesterday that they’re prepping a private hotfix for our grey screen issue

The issue is not resolved yet, I try to get the private hotfix. @Balint Oberrauch: The article you mentioned unfortunately did not help… @Rody Kossen: Are you aware of a grey screen issue with VDA 2407, if so, any chance to try the private fix in a test environment at the customer?

@Dennis Did you create a CDF trace of the issue? Also, what is your case number?

We have no case open yet, I will try to create a CDF trace.

Let me know once you have it, happy to take a look at it

Meanwhile I was able to create a CDF trace, the responsible at the customer is on vacation, he had no time to open a case yet. I will DM you the CDF trace if you want to take a look.