Liquidware ProfileUnity DriveMapping Slow mapping for Admins on Microsoft Windows 11 24H2 and 25H2

Why does a ProfileUnity drive mapping take 25 to 30 seconds at logon, but only for users who are local administrators?

On Windows 11 24H2 and 25H2, a ProfileUnity drive mapping can stall for about 30 seconds at logon for users who are members of the local Administrators group. The same mapping is instant for standard users. This article explains the cause, how to confirm it, and how to resolve it.

Symptoms

• Logon pauses on the ProfileUnity splash at Drive Mapping for 25 to 30 seconds.
• The ProfileUnity log client_DriveMapping_Logon_*.log shows a long Stop DriveMappingModule.Connect (for example 00:00:30.0474444) followed by connect completed = True. The mapping succeeds; it is only slow.
• Only users who are local administrators are affected. Removing the user from the local Administrators group makes the mapping fast.
• The share itself responds quickly: DriveMappingModule.EnsurePathExists completes in milliseconds, and other drives to the same file server map instantly.
• The Application event log shows Event ID 1000 for ShellHost.exe with faulting module ControlCenter.dll and exception code 0xc0000409, around 30 to 40 seconds after logon. Quick Settings (Win+A) may not open right after logon.

Cause

Three conditions together cause the delay:

1. ShellHost.exe hangs at logon. On affected Windows 11 24H2 and 25H2 builds, the Windows package Microsoft.UI.Xaml.CBS is not registered for the user in time. ShellHost (Quick Settings / Control Center) keeps retrying, stops responding, and crashes after about 30 seconds. Microsoft documents this in KB5072911.
2. ProfileUnity maps drives with elevated rights. For a local administrator, the ProfileUnity elevation service runs the logon client with the user's linked (elevated) UAC token. The drive is therefore created in the user's elevated logon session.
3. EnableLinkedConnections is enabled. ProfileUnity sets HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLinkedConnections = 1 at startup, so that drives mapped in the elevated session are also visible in Explorer. In this linked-connection path, the elevated mapping call does not return until ShellHost responds. With a hung ShellHost, that is when ShellHost crashes.

Standard users have no linked token, so the linked-connection path is not used and the mapping is immediate.

Liquidware reproduced this on Windows 11 25H2 by suspending ShellHost.exe and mapping a drive with the same API ProfileUnity uses:

How to Confirm

Log on with an affected administrator account, wait one minute, and check the following.

In the ProfileUnity log folder (%TEMP%\ProfileUnity), find the duration of the slow mapping:

Select-String -Path "$env:TEMP\ProfileUnity\client_DriveMapping_Logon_*.log" -Pattern 'Stop DriveMappingModule.Connect'

Check the Application event log for ShellHost crashes in the last 15 minutes:

Get-WinEvent -FilterHashtable @{LogName='Application'; Id=1000; StartTime=(Get-Date).AddMinutes(-15)} |
  Where-Object Message -match 'ShellHost' | Select-Object TimeCreated, Message

The issue is confirmed when the mapping takes 25 to 30 seconds and a ShellHost.exe / ControlCenter.dll crash is logged around the same time.

Resolution

The fix is on the Windows side: make sure ShellHost does not hang at logon. Start with step 1, and use step 2 only if the issue remains after the update.

1. Install the latest Windows cumulative update

Microsoft states in KB5072911 that the issue is addressed in Windows updates released from June 23, 2026, and that the resolution is rolled out gradually. Install the latest cumulative update on one test device, restart, and log on twice with an administrator account. The first logon after an update can differ. Then verify the result as described in step 3.

2. Register the shell XAML packages at logon

If ShellHost still crashes after the update, apply the workaround from KB5072911: register the three shell packages for the user at every logon, before the drive mappings run. In ProfileUnity, add a User Defined Script that runs in the Logon > Pre phase (before the other modules) with Wait for completion enabled.

Executable: powershell.exe. Arguments (adjust the share path):

-NoProfile -ExecutionPolicy Bypass -WindowStyle Hidden -File "\\server\share\Register-ShellXamlPackages.ps1"

Content of Register-ShellXamlPackages.ps1. It only registers packages that are not yet registered for the user and writes a log to %TEMP%\Register-ShellXamlPackages.log:

$log = Join-Path $env:TEMP 'Register-ShellXamlPackages.log'
$packages = @{
    'MicrosoftWindows.Client.CBS'  = 'MicrosoftWindows.Client.CBS_cw5n1h2txyewy'
    'Microsoft.UI.Xaml.CBS'        = 'Microsoft.UI.Xaml.CBS_8wekyb3d8bbwe'
    'MicrosoftWindows.Client.Core' = 'MicrosoftWindows.Client.Core_cw5n1h2txyewy'
}
foreach ($name in $packages.Keys) {
    if (Get-AppxPackage -Name $name) { "$(Get-Date -f s) skip $name (registered)" | Add-Content $log; continue }
    $manifest = "$env:SystemRoot\SystemApps\$($packages[$name])\appxmanifest.xml"
    try {
        Add-AppxPackage -Register -Path $manifest -DisableDevelopmentMode -ErrorAction Stop
        "$(Get-Date -f s) OK   $name registered" | Add-Content $log
    } catch {
        "$(Get-Date -f s) ERROR $name : $($_.Exception.Message)" | Add-Content $log
    }
}

3. Verify the result

Log on with an administrator account and repeat the checks from How to Confirm:

• Stop DriveMappingModule.Connect is under one second.
• No Event ID 1000 for ShellHost.exe / ControlCenter.dll at logon.
• Quick Settings (Win+A) opens immediately.
• If you used step 2: the script log shows OK or skip for each package and no ERROR lines.

What Not to Do

Removing users from the local Administrators group also avoids the delay, but it is an organizational decision rather than a fix.

Troubleshooting

• If a drive mapping is slow for all users, or no ShellHost crash is logged, this article does not apply. Check name resolution, Kerberos and access to the share first.
• For the Windows issue itself, see Microsoft KB5072911.
• If the issue remains after steps 1 and 2, collect a ProfileUnity Client Diagnostic bundle from an affected logon (with the logon user still signed in) and contact Liquidware Support.