Here are some simple techniques that can help you troubleshoot event ID 18456 sa.
4 minutes to read.
Details
SQL Readability Data Table = “1”>
attribute
value
product server
Event ID
18456
Event Source
MSSQLSERVER
component
SQL Engine
Symbolic name
LOGON_FAILED
Message text
Login for user ‘%. * ls’.%. * ls failed
Explanation
If the login attempt is rejected due to an authentication error containing an invalid password or username, a similar message is returned to the client:”The user ‘‘ could not enter the production environment. (Microsoft SQL Server Error: 18456) “.
Additional Error Information
For security reasons, the increased number of error messages returned to the entire client intentionally masks the nature of the authentication error. However, the corresponding error in the SQL Server error log contains an error status associated with a certification error condition. Compare the error status with the following list to determine what caused the connection error: Readabilitydatatable = “1”>
State
Description
1
error
2
A valid user ID.
5
Invalid user ID.
6
An attempt was made to use a Windows login in combination with SQL Server Authentication.
7
Connection disconnectedchenno and incorrect password.
8
Invalid password.
9
Invalid password.
11
The connection is valid, but access to the server has failed. One possible reason for the following error is that the Windows user has access to SQL Server as a member of the local Administrators group, but Windows definitely does not provide administrator credentials. To establish a connection, start the Connect utility with the Administrator’s Run option, and then add most Windows users to SQL Server with the specified login.
12
The connection is valid, but direct access to the server failed.
18
The password needs to be changed.
38, 46
Definitely managed to find the database requested by the user.
58
If SQL Server is configured to use Windows Authentication only and the client also tries to connect using SQL Authentication. Another reason is that the SIDs do not match.
102-111
AAD error.
122-124
Error due to blank or requested username security password
126
The user database probably does not exist.
132-133
AAD error.
Other error conditions and survivability indicate an unexpected internal processing error.
Cause of error The connection attempt with SQL authentication failed. The server is configured only during Windows authentication. can be returned in the following situations.
If the server is configured to search in mixed mode authentication, and the ODBC federation uses TCP, and the binding does not explicitly indicate that it is communicating. must use a trusted connection.
If the Internet is configured for mixed mode and authorization, the ODBC connection uses named pipes, not to mention the credentials the client used to unlock the named pipes to instantly determine that the user is taking ownership and the connection is established. explicitly indicate that the connection should use a trusted connection.
To resolve this issue, add TRUSTED_CONNECTION = TRUE to the connection flow.
Examples
In this example, the authentication error message is 8. This means that the master password is incorrect.
Date
Source
Message
2007-12-05 20:12: 56.34
Register
Error: 18456, Severity: 16, Status: 8.
2007-12-05 20:12: 56.34
Register
Connection for operator PC “” failed. [CLIENT:]
The User You Are Activating
If you are trying to connect using SQL Server Authentication, check which SQL Server is configured for Mixed Authentication. For more information about changing the SQL Server Authentication Mode, see Changing the Server Verification Mode
If you are trying to log on using SQL Server Authentication, make sure the SQL Server login exists and that you spell it correctly.
If you are trying to login using Window Authentications, make sure you are successfully logged into the correct domain.
If your personal error indicates status 1, contact your SQL Server administrator.
If you are trying to use administrator credentials, run the application using the “Run as administrator” policy. When you are logged in, add the new resource to your Windows user as an individual logon.
If the Database Engine supports stand-alone databases, ensure that the login was not deleted after navigating to the secure database user.
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If SQL Server is installed in Windows authentication mode and then switched to SQL Server and Windows authentication mode, your sa connection is initially disabled. This causes the condition7 “Connection error: user sa error”. For more information on enabling sa get access, see Changing Server Authentication Mode .
Step 1. Log in using Remote Desktop.Step 2. Start the administration of Microsoft SQL Server.Step 3: Check the server authentication mode.Step 4: restart the SQL service.Step 5. Check SQL user permissions.Step 6: Map the user to the database.
The generic message “Login failed for user (Microsoft SQL Server, error: 18456)” means that you must enter invalid credentials when logging into SQL Server. In the screenshot below, I am logging into Microsoft SQL ServerManagement Studio with a user who not only has administrator rights to log into the server.
Right click on your server.Access to the security option.Activate the option “SQL Server and Windows Authentication Mode”Click the OK button.
