Login to Microsoft SQL Server Error: 18456

I am getting this error while trying to connect to the SQL Server.

>Microsoft SQL Server Error: 18456

Can anybody tell me what the error code means?

Before opening, right-click and choose 'Run as Administrator'. This solved the problem for me.

first see the details of the error
if "state" is "1"
Ensure the database is set for both SQL and Windows authentication under SQL server / Properties / Security.

for other state see the above answers ....

1. Check whether mixed mode authentication is enabled in you server->properties
2. Then create a login in the server->security
3. create an user for that login in your database
4. Then restart your server by right clicking the instance and select restart

If you change a login user credential or add new login user then after you need to log in then you will have to restart the SQL Server Service. for that

GO to--> Services
[![gray color row][1]][1]


[1]:

Then go to SQL Server(MSSQLSERVER) and stop and start again

Now try to log in, I hope You can.

Thanks

Right Click the User, go to properties, change the default database to master
This is the screen print of the image which shows what you have to check if you have the error 19456. Sometimes it default to a database which the user doesn't have permission


[1]:

If you're trying to connect using "SQL Server Authentication" then you may want to modify your server authentication:

Within the Microsoft SQL Server Management Studio in the object explorer:

1. Right click on the server and click `Properties`

2. Go to the `Security` page

3. Under `Server authentication` choose the `SQL Server and Windows Authentication mode` radio button

4. Click `OK `

5. Restart SQL Services

18456 Error State List

ERROR STATE ERROR DESCRIPTION


- State 2 and State 5 Invalid userid
- State 6 Attempt to use a Windows login name with SQL Authentication
- State 7 Login disabled and password mismatch
- State 8 Password mismatch
- State 9 Invalid password
- State 11 and State 12 Valid login but server access failure
- State 13 SQL Server service paused
- State 18 Change password required

Potential causes
Below is a list of reasons and some brief explanation what to do:

**SQL Authentication not enabled**: If you use SQL Login for the first time on SQL Server instance than very often error 18456 occurs because server might be set in Windows Authentication mode (only).

*How to fix*? Check this [SQL Server and Windows Authentication Mode page.][1]


**Invalid userID:** SQL Server is not able to find the specified UserID on the server you are trying to get. The most common cause is that this userID hasn’t been granted access on the server but this could be also a simple typo or you accidentally are trying to connect to different server (Typical if you use more than one server)

**Invalid password:** Wrong password or just a typo. Remember that this username can have different passwords on different servers.

**less common errors:** The userID might be disabled on the server. Windows login was provided for SQL Authentication (change to Windows Authentication. If you use SSMS you might have to run as different user to use this option). Password might have expired and probably several other reasons…. If you know of any other ones let me know.

**18456 state 1 explanations:** Usually Microsoft SQL Server will give you error state 1 which actually does not mean anything apart from that you have 18456 error. State 1 is used to hide actual state in order to protect the system, which to me makes sense. Below is a list with all different states and for more information about retrieving accurate states visit [Understanding "login failed" (Error 18456) error messages in SQL Server 2005][2]


Hope that helps


[1]:

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[2]:

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Please check to see if you are connected to the network if this is a domain member PC. Also, make sure you are not on a dual home PC as your routes may be incorrect due to network metrics. I had this issue when I could not connect to the domain the SQL windows authentication switched to the local PC account but registered it as a SQL authentication. Once I disabled my wireless adapter and rebooted, the Windows integration switched back to the domain account and authenticated fine. I had already set up Mixed mode as you had already done as well so the previous posts do not apply.

I believe this can happen if you are trying to log in with a user that is defined in Active Directory, but attempt using "SQL Server Authentication" in the login screen. I do not know how to specify a different user with NTLM/Windows Authentication: When I click the Windows Authentication dropdown, the username and password is blanked out, and I can only log in as myself.