Windows 10: "We can't sign into your account" easy fix.

Recently I have encountered the Windows 10 error "We can't sign into your account", particularly after the recent Windows updates. Instead of fiddling around with multiple reboots and going into safe mode, try this first:
Step 1: Open "File Explorer" and go to the C: drive "Users" folder.

Step 2: Right-click on the folder that corresponds to the user account you were trying to log in as (i.e. DoctorZW). Select "Properties" and then "Security"

Step 3: Click on the "Advanced" button to get to the following screen:

Step 4: You will probably see that the "Owner" is set to "SYSTEM". Click on the "Change" link and type in "administrators" and click on "Check Names".

Step 5: If the administrators group can be found it will be displayed with its full name. Click "OK" and then check the box "Replace owner on subcontainers and objects" and "Replace all child object permission entries with inheritable permission entries from this object". Finally, click "OK"

Step 6: Answer "Yes" to the two confirmation dialog boxes and wait while the changes are applied. Depending on the volume of user data, this could take a long time.
Step 7: Click "OK" from the "Security" dialog box.
Step 8: Log off and try logging on as normal. If the "Log off" option is not available, then select "Restart" instead. This is important.
This approach has worked for me on all the PCs I have tried it on. Your next login should be succesful and return you to your normal desktop.