Common login issues and how to fix them!

Description
The registration key stores shortcuts from the user's Start menu, but due to a bug, the entries are added again every time the user logs in. This can quickly result in thousands of entries. However, the entire registry key is also read every time the user logs in, and this process takes increasingly longer—sometimes up to several minutes. 

This error occurred in Windows 2008 R2 is well-known and continues to exist with Windows Server 2016 and 2019.

Solution
To resolve the issue, delete the entire key via Group Policy at each login and also exclude the key using Citrix UPM.

References

• Slow logon with a blank screen in Windows 7 or Windows 8.1
  https://docs.microsoft.com/en-us/troubleshoot/windows-client/user-profiles-and-logon/slow-logon-with-blank-screen 
• Slow Logon with a Black Screen in XenDesktop Server VDA
  https://support.citrix.com/article/CTX212905 

Citrix UPM and the App Preparation Service

Description
Microsoft has introduced a new Windows service: App Readiness. The purpose of this service is to „get apps ready for use the first time a user signs in to this PC and when adding new apps.“. 
However, this service is unnecessary on multi-user systems (RDS). Nevertheless, the App Preparation service is active, and due to an error in the Citrix User Profile Manager (UPM) service, it has deleted the registry values for App Preparation. This then leads to long login times (minutes), often accompanied by a black screen.

Solution
Since this service is not necessary on multi-user systems, it can be disabled via Group Policy.

References

• Users see a black screen when logging in to Published Desktop
  https://support.citrix.com/article/CTX272201 

Recently used Windows and Office files 

Description

Recently used Windows and Office files are stored in small files within the user profile. The number of these hidden files can grow so large that it may take several minutes to log in. Since the number of files depends heavily on user behavior, the extent to which users are affected can vary.

Overall, this also appears to be a bug, as I have only encountered this issue with a few customers. Setting the GPO to limit the most recently used files does not help, since this only affects the display of the files and not how many should remain. In Citrix Director, this can often be identified as a large time difference between the total time and the individual times. 

Solution
Users will likely want to see the most recent 20 files, so not all files can be deleted. Scripts and similar tools can help adjust the number of files for each user on a daily basis.

The Firewall Rules Bug

Description
Windows Server 2016/2019 has a bug that creates local firewall rules every time a user logs in. Over time, this slows down the login process and can also cause the entire system to lose performance. This often adds a few seconds to the interactive login process in Citrix Director.

Solution
Microsoft released an update for this in March 2019 (KB4490481), but you also need to manually set a registry value!

HKLM\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy
DeleteUserAppContainersOnLogoff REG_DWORD = 0x00000001

In addition, there may already be thousands of rules in place, and those need to be cleaned up as well. The PoSh script below can be used for this purpose.

References

• March 26, 2019—KB4490481 (OS Build 17763.402)
  https://support.microsoft.com/en-us/help/4490481/windows-10-update-kb4490481
• Removes unwanted FW rules: ClearFWRules.zip 
   

GPO with „dead“ network drives or network printers

Description
Users who connect to network shares or network printers via Group Policy may experience 30-second delays during login. This happens whenever the network resource is no longer available. 

Solution
The goal here is to identify the network resources that are no longer available and to disable or delete them in Group Policy. The Group Policy event log on the server where the user is logged in can be helpful in this regard.