Issue

After upgrading Windows 10 to 20H2 version, a user can no longer log-in with his account. The following error message is displayed.

The User Profile Service service failed the sign-in.
User profile cannot be loaded.

Resolution

In this particular case, after a reboot, the affected user could log in, but Windows was loading a temporary profile so nothing saved in the user’s normal profile was accessible. If you still can’t log in after a reboot, you can try safe-mode or log in as another user.

• Open Registry Editor (regedit.exe).
• Navigate to HKEY_LOCAL_MACHINE > SOFTWARE > Microsoft > Windows NT > CurrentVersion > ProfileList
• Find which Key (starting S-1-5) within ProfileList corresponds to the corrupted profile. To do that, check ProfileImagePath entry which should point to the correct user’s profile location, i.e. C:\Users\john.smith.
  In my case, the key had .bak extension, while the other key with the same SSID number (without .bak) had ProfileImagePath pointing to the temporary profile location.
• To fix the issue:
  • Rename the key pointing to a temporary profile by adding .bak2 at the end.
  • Rename they key with the correct profile path by removing .bak from the end.
  • Inside the key with a correct profile path (now without .bak), find State entry and change its value to 0.
• Reboot the computer and try logging in again.

In this particular case, the above steps fixed the issue. The user could log in and the correct profile was loaded.

November 2020
Windows 10 Pro (20H2)