Microsoft SQL Server Error 18456
This is one of the basic errors associated with SOL server where it fails to authenticate the communication between the client and the server. If you are a Database administrator you must have faced this error many a times in your life. The basic reason for this error is the client’s failure to connect with the server.
How to log SQL server Errors?
Almost all versions of SQL server are configured to log all events of the residing state of the application. To be more specific you can configure your system to log the following auditing options for SQL login:
- Failed Login only
- Successful Login only
- Both Failed and Successful Logins
- None
To configure these options you can check out the official Microsoft help library.
How to Access Log files in SQL server?
So now that you know how to configure the logs, the next step would be to find the file manually to access them. This how it can be done:
Windows Event Viewer
In order to access the Windows Event viewer follow these steps:
- Go To start
- Find “Run”
- Type “Eventvwr”
- Select the “Application” from the Windows Log
- Find Login failed Error Messages
- Check the information for exact details
SQL Error Log
If you are able to log into the SQL server you can use the “sp_readerrorlog”, “xp_readerrorlog” files or directly use the GUI interface to read the Error log file.
- Open Management Studio
- Find SQL server Logs
- Select View
- SQL Server Log.
If you are unable to log into the SQL server or it has accidently crashed, you will have to use the absolute error path and manually open the text log.
- Open SQL configuration Manager
- Select the “Advanced” tab
- Find “Startup Parameters”
- Copy the path up to the “master.mdf”
- Open using Notepad
SQL Server Error 18456 State
The following table describes every error related with 18456:
| SQL STATE | STATE DESCRIPTION |
| 1 | Generic Error Message |
| 2 & 5 | Invalid username |
| 6 | Mismatch Windows login name to SQL Authentication process |
| 7 | Password Mismatch and Disabled Login |
| 8 | Password don’t match |
| 9 | Password not valid |
| 10 | Very Rare Error/ Check MS Support |
| 11 & 12 | Login Validated and Server Error |
| 13 | SQL Server service paused |
| 16 | Login have No access to User Database |
| 18 | Change Password Required |
| 23 | SQL server shutting down simulation while incoming request is made |
| 38 | Database does not exist or Access not granted (Server 2008 and above) |
| 40 | Default Login database not found |
| 58 | SQL server login is used mistakenly against Windows Authentication mode |
Other Similar Errors
This is list of errors which might show up while you encounter errors with 18456 state. We have listed all the error description associated with their respective error number.
| Error Number | Error Description |
| 18451 | Only Admin Login Allowed |
| 18452 | Login from un-trusted Domain |
| 18458 | Max number of Simultaneous Users reached |
| 18459 | Workstation Licence limit reached |
| 18460 | Additional Licence required for workstation |
| 18461 | Server Currently running under Single User mode |
| 18462, 18463 | The login failed for user “%.*ls“. The password change failed. The password for the user is too recent to change. %.*ls |
| 18464, 18465, 18466 | Password too short/long/complex as per Windows Policy requirement |
| 18467 | Password does not meet the requirement pf Password Filter DLL |
| 18468 | An unexpected error has occurred |
| 18470 | Account has been Disabled |
| 18471 | The users does not have the permission to change the Password |
| 18482 | Incorrect Remote Server name |
| 18483 | Incorrect Login name for the remote server |
| 18485 | Server does not accept remote login |
| 18486 | Account Locked out |
| 18487 | Account Password Expired |
| 18488 | Account password must be changed |
| 18489 | Dedicated Admin connection currently in Use |
If you are facing any problem with these errors you can ask for help in the comment section.