When an SQL Server is started for the first time, there is a possibility that ‘Windows authentication’ is enabled under the security option.

If the above solutions do not work for you, then you should run some basic troubleshooting methods.

The password of your SQL account is incorrect and the administrator may assign you the new credentials.

Contact the administrator and get help with the issue.

If the error is not showing any description but shows that the administrator has not authorized you to get the details of the error.

The username and password may have changed and the user should contact the administrator for the new credentials.

Perhaps you are using SQ Server Authentication but Windows Authentication set for the user.

The authentication mode would be different.

The user account may not exist in the SQL Server.

Probable causes and of SQL server login error code 18456 But genuine users may find it hard to overcome the problem. This error may be interpreted as a mechanism to prevent unauthorized persons from accessing the server by guessing the credentials. However, administrators can check the error details in the event log to get a clear picture of the problem. And the error message displayed does not define the reason. Generally, it happens even if the username is accepted. Microsoft SQL Server error code 18456 denotes a failed login attempt which may be due to an incorrect password entry. Generally, the user name is accepted but the password is considered false. The above issue can happen to any SQL Server user and make it impossible to access your server and the saved databases. But the user is not able to connect with the server.”

We always use SQL Server authentication and provide valid credentials. But one of our team members started getting the error that login failed for the user. “ We have been using SQL Server to manage our databases for a long time and update it with the latest version as soon it gets updates.

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