Hello Irin Sultana,
There could be a multitude of reasons why you are receiving this login error message.
To narrow down the cause, I'd recommend to review the security events on the server for the failed attempts in question. Details on events below could tell you the reason, as example "User logon with misspelled or bad user account", "User logon to account disabled by administrator", etc.
Check those:
- 4625 (4625(F): An account failed to log on)
- 4624 (4624(S): An account was successfully logged on)
- 4776 (4776(S, F): The computer attempted to validate the credentials for an account)
As example, event 4625 is logged for any logon failure. It generates on the computer where logon attempt was made, for example, if logon attempt was made on user's workstation, then event will be logged on this workstation. This event generates on domain controllers, member servers, and workstations.
Kindly mark the answer as Accepted and Upvote in case it helped!
Regards,
Olga Os.