After nearly half a year of looking for solution, I found it. There are other post related to this issue, but they are closed and the accepted answers did not resolve the issue for me and others.
Background: Surface Pro 4 with Windows 10, domain joined. Facial recognition worked for over six months. Then some updates were pushed out and it stopped working. I came across a post that indicated to remove both the PIN and the facial recognition in the sign in options page. Issue was there was no remove button for the PIN. This proved to the 'brick wall'. I finally located a post that showed how to remove the PIN from Windows 10 without the remove button. Once I had the PIN removed I was able to create a new facial recognition profile and add a new PIN. After that, facial recognition was working again.
I posted a version of this elsewhere for removing the PIN. Here is the revamped version for resetting facial recognition.
!CAUTION! Proceed at your own risk. Ensure you have your system backed up. This worked for me on multiple systems. It does not mean it will work for you or not cause any problems.
- Use your password to log in to Windows 10.
- Go into Settings (click on start and select settings).
- Select accounts.
- In the left pane select Sign-in options.
- Under 'Face Recognition', click remove.
- Under PIN, click 'Remove'.
- At this point, reboot and again add facial recognition. However, if there is no remove button, which likely why you are reading this, then proceed to the following steps.
- Open Control Panel.
- In Control Panel open 'File Explorer Options'.
- In the View tab under Advanced Settings, select Show hidden files and uncheck 'Hide protected operating system files'.
- Open File Explorer and browse to this path:
- Right click
Ngcfolder and choose Properties.
- Navigate to Security tab and click on Advanced button.
- Locate the Owner section at the top and click Change link.
- In the 'From this location' field, make sure it is the name of the computer. Click the Locations button to change if it is not.
- In the 'Enter the object name to select' field enter Administrators. Click on 'Check Names'. It should auto fill the full path for the Administrators group. Now click OK.
- Check 'Replace owner on subcontainers and objects' and click Apply and OK.
- Some folders cannot be deleted regardless of the owner. So, what I found works better is to simply rename the Ngc folder to something else, like Old_Ngc.
- Once the folder is renamed, create a new folder named Ngc.
- Close all of the windows and reboot.
- Once the system is rebooted, the sign-in options should now allow you create your facial profile and 'Add' a new PIN.
I have now applied this to several systems with success on all.
I hope this helps others who have run into this problem. Hopefully MS will fix this at some point or provide an easier method to fix it when it happens.