title: SQL Server login successfully in windows authentication mode but fail in SQL Server authentication mode
body: <p>I have checked my server is SQL Server and Windows Authentication mode.</p>
  
  <p>I am a sa for this server.  </p>
  
  <p>I can login successfully in windows authentication. I also create an account but fail to login SQL Server authentication.</p>
  
  <p>I share this sqlserver account and password to others and they can login successfully.
  Why does it happen ?
  the error log is: 18456, state 1.</p>
  
  <hr>
  
  <p>Error Number: 18456
  Severity: 14
  State: 1
  Line Number: 65536</p>
  
  <hr>
  
  <p>Program Location:</p>
  
  <p>at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, DbConnectionPool pool, String accessToken, Boolean applyTransientFaultHandling)
     at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
     at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup, DbConnectionOptions userOptions)
     at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource<code>1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal&amp; connection)
     at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource</code>1 retry, DbConnectionOptions userOptions)
     at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource<code>1 retry, DbConnectionOptions userOptions)
     at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource</code>1 retry)
     at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
     at System.Data.SqlClient.SqlConnection.Open()
     at Microsoft.SqlServer.Management.SqlStudio.Explorer.ObjectExplorerService.ValidateConnection(UIConnectionInfo ci, IServerType server)
     at Microsoft.SqlServer.Management.UI.ConnectionDlg.Connector.ConnectionThreadUser()</p>