A connection was successfully established with the server, but then an error occurred during the login process. (Error Number: 233)

Question

I am having error while connecting to SQL Server:

Details in Stack Trace are:

===================================

Cannot connect to ServerN         


        

Answer 1

When you starting application 'Run as administrator'.This way I avoided this error.

Answer 2

To add on top of @Pranav Singh and @Rahul Tripathi answer. After doing all the mentioned by those 2 users, my .net app still wasnt connecting to the database. My solution was.

Open Sql Server Configuration Manager, go to Network configuration of SQL SERVER, click on protocols, right click on TCP/IP and select enabled. I also right clicked on it opened properties, Ip directions, and scrolled to the bottom (IPAII , and there in TCP Port, I did setup a port (1433 is supposed to be default))

Answer 3

the following points work for me. Try:

1. start SSMS as administrator
2. make sure SQL services are running. Change startup type to 'Automatic'

3. In SSMS, in service instance property table, enable below:

Answer 4

I've gotten this error because the user trying to login was lacking permissions.

I don't recommend doing this, but I fixed it by granting the user db_owner globally. It was a local instance, so not a huge security concern.

Answer 5

For SQL2008,

• open Management Studio
• Rt click on instance
• go to properties
• select Security
• Under Server Authentication, check SQL Server and Windows Authentication Mode
• hit OK

Restart the server using configuration manager.

Answer 6

Sometimes specifying the database (instead of default) solves this error.