Login to Microsoft SQL Server Error: 18456

Question

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

Microsoft SQL Server Error: 18456

Can anybody tell me what th

Answer 1

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.

Answer 2

First go to start bar then search local services Then click on "view local services" Then it will open service window then go to SQL Server(MSSQLSERVER) right click on it and click on stop and then again right click on it and click start. Now you can able to login and put your user name as 'sa' and password is your won password.

Answer 3

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

Answer 4

Just happened to me, and turned out to be different than all other cases listed here.

I happen to have two virtual servers hosted in the same cluster, each with it own IP address. The host configured one of the servers to be the SQL Server, and the other to be the Web server. However, SQL Server is installed and running on both. The host forgot to mention which of the servers is the SQL and which is the Web, so I just assumed the first is Web, second is SQL.

When I connected to the (what I thought is) SQL Server and tried to connect via SSMS, choosing Windows Authentication, I got the error mentioned in this question. After pulling lots of hairs, I went over all the setting, including SQL Server Network Configuration, Protocols for MSSQLSERVER:

Double clicking the TCP/IP gave me this:

The IP address was of the other virtual server! This finally made me realize I simply confused between the servers, and all worked well on the second server.

Answer 5

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

Answer 6

I have faced the same issue. You need to enable the Mixed Mode Authentication first. For more details How to enable Mixed Mode Authentication