Logon failed for login 'ABC' due to trigger execution.

All of a sudden developers complained about issue.

System.Data.Entity.Core.EntityException: The underlying provider failed on Open. ---> System.Data.SqlClient.SqlException: Logon failed for login 'ABC' due to trigger execution.

Changed database context to 'XYZ'.

Changed language setting to us_english.

Solution:

I DISABLED TRIGGER. 

Help:

http://blog.sqlauthority.com/2009/06/27/sql-server-fix-error-17892-logon-failed-for-login-due-to-trigger-execution-changed-database-context-to-master/

I used below trigger to test and find out login information .

USE [master]

GO

SET ANSI_NULLS ON

GO

SET QUOTED_IDENTIFIER ON

GO

CREATE TRIGGER [Trigger_ServerLogon]

ON ALL SERVER FOR LOGON

AS

BEGIN

DECLARE @data XML

SET @data = EVENTDATA()

INSERT INTO dbo.ServerLogonHistory

SELECT @data.value('(/EVENT_INSTANCE/EventType)[1]', 'nvarchar(512)')

, @data.value('(/EVENT_INSTANCE/PostTime)[1]', 'datetime')

, @data.value('(/EVENT_INSTANCE/SPID)[1]', 'nvarchar(4)')

, @data.value('(/EVENT_INSTANCE/ServerName)[1]', 'nvarchar(512)')

, @data.value('(/EVENT_INSTANCE/LoginName)[1]', 'nvarchar(512)')

, @data.value('(/EVENT_INSTANCE/LoginType)[1]', 'nvarchar(512)')

, @data.value('(/EVENT_INSTANCE/SID)[1]', 'nvarchar(512)')

, @data.value('(/EVENT_INSTANCE/ClientHost)[1]', 'nvarchar(512)')

, @data.value('(/EVENT_INSTANCE/IsPooled)[1]', 'nvarchar(1)')

END

GO

DISABLE TRIGGER [Trigger_ServerLogon] ON ALL SERVER

GO