You could also check your background apps in Privacy settings, as some might be set to run automatically and access the camera. Another option is to look for your camera's specific software, as it might have its own activity light control.
Agreed. Yeah, that error code usually points to a permissions issue—have you tried running the Windows troubleshooter for privacy settings? Let me know if that works.
You could also try manually resetting the Windows permissions service through the command prompt. Another option is to check if a system restore point from before the upgrade is available.
I had the same problem. After my upgrade, all my location and diagnostic settings reverted too, and it took me forever to go through and lock everything back down.
Agreed. Yeah, that's a common headache. A quick tip: run the privacy troubleshooter in Settings > System > Troubleshoot—it sometimes fixes those permission errors.