FSLogix black screen at login

Ouwerhyys 6 Reputation points

We are running FSlogix Office 365 containers in our Citrix Virtual Apps and Desktops 1912 CU1 environment with Windows 10 1909.

When a user logs in for the first time she/he sees a black screen for 3-5 minutes before the desktop with icons is displayed. On event viewer the following warning is logged:

The winlogon notification subscriber <frxsvc> took 272 second(s) to handle the notification event (StartShell).

%ProgramData%\FSLogix\Logs\ODFC The log starts 09:18:47 and stops 09:23:20, so it does something for nearly 5 minutes:

[09:18:47.961][tid:00000d50.000015fc][INFO] ===== Begin Session: Attach Outlook Data Folder Container: user1
[09:23:20.349][tid:00000d50.000015fc][INFO] ===== End Session: Attach Outlook Data Folder Container: user1

The black screen stays "ONLY" for 10-30 seconds on second login and the ones after that.

None of the solutions presented here have solved the issue:


We're not using Windows Defender, it is disabled with a GPO so this is not a Defender issue. We also removed our antivirus solution and tested login after that, but it didn't change anything. We also reinstalled the Citrix VDA client -> no change, updated FSLogix to version 2.9.7621.30127 -> no change, disabled App Readiness service -> no change.

If we remove FSLogix and login after that we do not see the black screen. When FSLogix is removed we can also see from Citrix Director that the login time is cut in half compared to when FSLogix is installed.

A set of solutions that enhance, enable, and simplify non-persistent Windows computing environments and may also be used to create more portable computing sessions when using physical devices.
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  1. FINISHDAAFIGHT 1 Reputation point


    Did you ever find a solution to this problem? We are having the same issue. Only with us, we are using profile container instead of outlook office container.

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  2. Ouwerhyys 6 Reputation points


    our problem was related to slowness of the file server to which we stored the o365 containers. Here's how I tested this (Non-persistent win10 desktops allocated with MCS):

    Checked logs from C:\ProgramData\FSLogix\Logs\ and found out that attaching the VHD(x) took a long time:

    VHD(x) attach request returning after 4359 milliseconds

    Changed the VHD Location Group Policy setting to point C:\Temp

    Made sure the MCS allocated desktops don't turn off after logoff by running the following PowerShell command on Delivery Controller:

    Set-BrokerDesktopGroup -Name "delivery group name" -ShutdownDesktopsAfterUse $false

    Logged in to the desktop after changing the VHD Location and didn't notice the black screen. The delay when attaching the VHD(x) also went down.

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  3. FINISHDAAFIGHT 1 Reputation point

    Good to know. We have tried both azure netapp files and azure blob storage with both having black screen issues as the vhd location. I guess keeping the vhd local is not a viable solution. Were you able to fix the file server issue and did the issue went away?

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  4. Ouwerhyys 6 Reputation points

    Yes I was able to fix the file server and now we're not seeing the black screen even though the "VHD location" is changed back to the file server. And yes, keeping the VHDX on local disk is not a viable solution, but changing the location temporarily to local might show you if the problem is related to the location where your VHDX is at.

    Check the logs to see if there's any hint about what's causing this. And in case of non-persistent Citrix desktops, when you change the power off setting and set all but one machine to maintenance mode, you can login/logoff to that machine and the logs don't disappear. Of course you can also set the log location elsewhere with a group policy.

    Here are the FSLogix log locations: https://learn.microsoft.com/en-us/fslogix/logging-diagnostics-reference

    Hope this helps.