Windows 10 occasionally fails to login after screen lock

Question

Occasionally (meaning, not always), after screen lock, login will fail on my Windows 10 desktop. I've tried looking online for possible solutions, but I find more topics about not being able to get to the login screen at all.

Steps to reproduce:

1. Lock screen
2. Press key/click to access login prompt
3. Enter anything for login information (either right or wrong password)
4. Wait some amount of time (>10s) with a spinner
5. Screen returns to lock

Reproduction rate: Very low, but once it occurs, it will continue to happen until restart.

Occasionally, I will also see a black screen with a cursor for a very short time after attempting unlock.

I'm not running any modifications to my lock screen. The amount of time locked doesn't seem to matter (it's happened within as little as 10min). So far, it only seems to happen after my computer has been on for a long time (weeks). The computer isn't frozen, since I can still attempt logins (and my applications and network connections are still open underneath, as verified from the network and other computers' clients). Unfortunately, it's Win10 home, so I can't attempt a remote desktop connection.

Not sure where to start looking for possible solutions to this problem, since I get so many results for other login screen issues.

Answer 1

Try unplugging any USB devices you have, such as wireless mice dongles (source). I also find that clicking the "Switch user" button in the lower left, then logging in with my regular username and password helps sometimes.

I have the same problem, but it occurs every time after I lock my screen...

Answer 2

I have had a similar problem for a while and I have discovered that after recent updates the keyboard mapping has changed from EN-UK to EN-US and some of the special characters I used in my password have changed in terms of which key they are 'on'. Looking back I think this was probably the reason why my password was not accepted. As I am not in front of the offending laptop just now I cannot check if there is a way to change the keyboard type prior to entering the screen-unlock password but an alternative would be to know which keys contain the correct characters for my password in each keyboard version.