Active Registered User suddenly unable to log in

[Lisa0413]

I have an active registered user who is suddenly unable to log in. In looking, their account settings are fine and they were able to log in yesterday.

As part of troubleshooting, reset password - same issue. Also tried logging into the account - same issue with standard message (i.e., You have entered an invalid username or password. Please enter the correct details and try again. Don't forget that the password is case sensitive. Forgotten your password? Click here! You have used 1 out of 5 login attempts. After all 5 have been used, you will be unable to login for 15 minutes).

Can anyone please advise further troubleshooting steps. Thanks!

[Wayne Luke]

Are you able to login with this user account?

[Lisa0413]

No, as I stated in my OP, I also tried to login with his user account and got the same error message. Oh, and no other users reporting issues (at this time, anyway).

[Wayne Luke]

What is the username? Does it contain any UTF-8 characters? You might try changing the username to English characters, at least temporarily to see if you can log in.

[Lisa0413]

No, simple username. Even tried to change username. Did not work.

[Lisa0413]

Just tried changing username and password again (both different from last attempt) and this time was able to log in ... so weird ...

Did anything change in a recent update that may have put restrictions on username and/or password syntax and may affect pre-existing accounts?

[Wayne Luke]

There have been no updates to the vBulletin Cloud code since we upgraded all sites to 5.4.3 almost two months ago.

There are no restrictions on username and password except what you have in place under Settings -> Options -> User Registration Options. The only hardcoded restriction is that the username and password cannot be the same.