Unified Write Filter - Maintenance Mode Stuck on Black Screen

Question

We're investigating using UWF instead of Faronics DeepFreeze, and up until now our tests with UWF were going fairly well. But on my first test of the maintenance mode I seemingly got a bunch of updates installed, followed by a black screen with mouse cursor. No keyboard inputs work (CTRL-ALT-DEL, etc) but pressing the power button will shut down the machine. Unfortunately, turning it back on results in the same black screen with cursor. I see numerous other posts online asking about this with no resolution, and it looks like it's been going on for many months, if not years. Is there a fix for this, and if not can we get some kind of response from an official MS rep to tell us whether or not we should ever expect a fix? I'm becoming increasingly annoyed with the lack of support for these extra tools MS dangles in front of us (like Provisioning), only to supply minimal documentation and no fixes to problems. Either commit to documenting and fixing a product or just don't release it. Seriously.

Answer 1

Hi,
There seems to be no relevant fix information at this time.
Also, you can use the Feedback Hub app to share your problem and wait for the next update.

If we have any updates or any thoughts about this issue, we will keep you posted as soon as possible.
Your kind understanding is appreciated.

Answer 2

I just recovered from a bad UWF Maintenance mode issue. Two PCs died the same way: after the overnight maintenance they stuck on spinning dotted circle in the early boot stage. Couldn't get to recovery mode by killing power 3-4 times.

1. I user a USB thumb drive with Windows 10 installation to get to recovery and fix the boot.
2. I got a black screen with mouse pointer running, not taking Alt-Ctrl-Del. I RDP'd to the PC and logged in!
3. I found a registry value that mentioned UWF Servicing and seemed to be blocking the logon screen, and removed it. Please be careful when editing Registry and make backup.
   HKCU\Software\Microsoft\WindowsNT\Current Version\Winlogon > delete Shell Reg_sz
   Hope it helps somebody to recover from the crash.

Answer 3

Further to this, since I was able to access the Event Logs remotely, I had a hunch that the computer wasn't totally broken. So on that black screen I just hit the spacebar, typed my password and hit Enter. I was logged in to the computer and now sit at the desktop. So it looks like this glitch is simply preventing the login screen from showing properly. Any thoughts on this? Edit: Interestingly, after a while with no input, the PC will lock itself and does show the lock screen just fine.

Edit
Here's a non-exhaustive list of what I've tried:

• Turn off fastboot.
• dism.exe /online /cleanup-image /restorehealth.
• Disabling all non-MS startup programs from MSconfig.
• Boot repair.
• Disabling the video device and deleting the driver.
• Uninstalling all the updates that I could.
• Safe mode with low-res graphics
• Disabling App Readiness in services.msc
• Checking that explorer.exe is set as the registry entry for HKEY_Local_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Winlogon.
• sfc /scannow
• And a couple less-likely culprits as well.

Answer 4

Hi,

I'm doing some testing with this on Windows 11 23H2 Enterprise. Interestingly, first time I run the servicing commands, it seems to work fine and reboots to the normal UWF-Servicing logon page. It never logs in automatically, however I think that is a known issue?

Second time I run the same servicing commands, I get the black screen on reboot. I can RDP into the machine, however otherwise it just seems to hang with a black screen indefinately.

uwfmgr.exe servicing enable
uwfmgr.exe filter restart

Has anyone found a fix or workaround? I am very keen to hear back from the community and anyone successfully using the Unified Write Filter (UWF) with Windows 11 and how they manage Windows Updates?

Answer 5

Hi,

I realise this is an old thread, however I wanted to post in case it helps someone. Jenny Feng's answer should not be the accepted answer. I have included some additional pieces of advise in addition to the black screen problem during UWF maintenance.

• The black screen issue reported here by Steve West. I have been able to replicate the issue, and from what I can see it only happens if you reset the password for the UWF-Servicing account. In a working environment there is no need to set the password for this account as its managed entirely by Windows and the UWF feature. Providing you do not manipulate the 'UWF-Servicing' local Windows user account or reset the password, you should be able to run the 'uwfmgr servicing enable' command to successfully complete the maintenance. Key takeaway, don't reset this password!
• Another common problem you may encounter is the Screensaver not showing up/or the maintenance window never completing!!! (which is why some of you may go down the rabbit hole of resetting the 'UWF-Servicing' password so you can login to see whats happening (Don't do that!!) You need to manually take ownership of c:\windows\system32\UwfServicingMasterScript.cmd and update the file as per the Microsoft article. https://learn.microsoft.com/en-us/windows/iot/iot-enterprise/customize/uwf-master-servicing-script. When you install the UWF Windows feature 'DISM.exe /Online /enable-Feature /all /FeatureName:client-UnifiedWriteFilter', the UwfServicingMasterScript.cmd file is actually outdated and includes some incompatible commands. Thank you to this thread for point this out to me: https://superuser.com/questions/1078646/unified-write-filter-servicing-on-windows-10-enterprise-not-working-as-expected
• Further to the above, the screen saver still doesn't appear until you actually push this reg key to the machine. The article says its to change the default settings for the UWF maintenance screen saver, however if you dont write the keys... the screen saver doesnt appear at all. I suggest deleting the ColorBackground, ColorText and ColorProgress lines, as they create some pretty awful colors if you try and change those. https://learn.microsoft.com/de-de/windows/iot/iot-enterprise/customize/uwf-servicing-screen-saver

With the above changes, it all seems to work quite well and the Windows updates get applied.

It would be great if Microsoft fixed some of these issues or at least updated the documentation to reflect these workaround.