Windows 20H2 update seems to have broken Windows Hello Face Recognition

Guess What? My camera is working on Windows 11. Problem solved!

Hi @per.larsson

I don’t know how you came to that conclusion but you would think that as a developer, one of the first 101 lessons you learn is to check if something went wrong when you perform an operation such as trying to open a file. When we consider that this biometrics data store is used by more than one service, there should be an API published by Microsoft to check for something like this. Further, if anyone can call a file open operation on such a delicate and sensitive area (biometric data of a person), you would think this API would ensure it is an authorised process trying to access it and not some suspicious process trying to access the store.

Of course, I am not a developer but all the above is based on common sense.

That said, the latest Microsoft update fixed the issue for me. Having said that, I have also uninstalled a bunch of apps that access the camera in an effort to eliminate the cause of the issue.

Unless an official Microsoft representative and preferably a developer in the biometrics space jumps in here, I guess all this is conjecture at best.

The problem I typically see is that the biometrics service is crashing when I'm trying to set up face-id, but I have also seen the device in use problem. Further, I just got a new laptop that has got a built-in IR camera, and fingerprint reader and it suffers from exactly the same problem. I cant set up either device. So although I and many of you you are experiencing this problem with the Logitec brio, it can be reproduced with other biometric devices as well.

The root cause for both the crash and device in use is likely the same.

I have not debugged this down to the line of code where the bug is; but the problem is with the file handle to the database file for the biometrics data.

Some-where the handle is swapped out for a handle to a different object. The file is opened, and some-time later the handle value is replaced with a handle to I believe an event-object. The crash occurs when the telemetry service is calling UnlockFileEx - since the handle is no longer referencing the file, but another object - causing an exception to be thrown.

And the device in use seem to be happening in a similar situation, by the service having opened the database file, and later when it closes the file the it's using the wrong handle, so it's not closing the file, but some other object. In this situation no exception is thrown, since when you close a handle - it doesn't matter what type of object the handle is referencing. When it later the service tries to open the file again it fails due to the file already being open - so you get the device in use error.

I'm sure on a system where you can reproduce this problem if you keep trying to use bio-devices you will see other problem as well, since like in the case of "device in use" the fact that some other random object has been closed - it will cause other problems as well.

In case people following this thread have not noticed yet, the latest Windows update fixed this issue, at least on my Surface Book 3 Business (update also contained several firmware updates).

My Logitech Brio camera now unlocks the computer upon facial recognition.

Facial recognition was broken again for the last couple of days, after working for a brief period of time after the last Windows update.

Once I disabled and re-enabled the "Windows Hello Face Software Device" in the Device Manager, it started working again.

I had a peak on this in a debugger (Since I have the same camera, and suffers from the same problem.)

It seem like there is a race condition // dangling handle error in WINBIOSTORAGEADAPTER.DLL.

The process is crashing due to UnlockFileEx throwing an INVALID_HANDLE exception.

And the reason for this is that the file handle passed to UnlockFileEx has been closed already by another thread. - So the handle is accessed after closure.

...

So.. We need Microsoft - to investigate this since it's their module.

Per Larsson, as there have been a few different issues raised here, which one is this? Does this align with the message when trying to set up the BRIO for Hello "Sorry, something went wrong. Camera is currently in use by another app. Close the app and try again." (when it's obviously not in use, as easily proven by the fact that it works with any other app started after this and by the fact that the attempt to set up Hello does turn on the camera red light) or one of the other reported problems using Brio 4k with Hello?

Currently, my hope is that a new install of the upcoming Windows 11 or the new Dell 4k camera will resolve the problem. I have lost any hope of the BRIO working on my desktop PC with Windows 10 Hello. I currently use a fingerprint reader with Hello, which is not as convenient as when the BRIO worked for Face Recognition, but it's not too bad. And the BRIO still works fine for everything else, just not with Hello.