title: A connection was successfully established with the server, but then an error occurred during the login process. (Error Number: 233)
body: <p>I am having error while connecting to SQL Server:</p>
  
  <p><a href="https://i.stack.imgur.com/FOQTX.png" rel="noreferrer"><img src="https://i.stack.imgur.com/FOQTX.png" alt="enter image description here"></a></p>
  
  <p>Details in Stack Trace are:</p>
  
  <pre><code>===================================
  
  Cannot connect to ServerName.
  
  ===================================
  
  A connection was successfully established with the server, but then an error occurred during the login process. (provider: Shared Memory Provider, error: 0 - No process is on the other end of the pipe.) (.Net SqlClient Data Provider)
  
  ------------------------------
  For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&amp;EvtSrc=MSSQLServer&amp;EvtID=233&amp;LinkId=20476
  
  ------------------------------
  Server Name: ServerName
  Error Number: 233
  Severity: 20
  State: 0
  
  
  ------------------------------
  Program Location:
  
     at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
     at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)
     at System.Data.SqlClient.TdsParserStateObject.ReadSniError(TdsParserStateObject stateObj, UInt32 error)
     at System.Data.SqlClient.TdsParserStateObject.ReadSni(DbAsyncResult asyncResult, TdsParserStateObject stateObj)
     at System.Data.SqlClient.TdsParserStateObject.ReadNetworkPacket()
     at System.Data.SqlClient.TdsParserStateObject.ReadBuffer()
     at System.Data.SqlClient.TdsParserStateObject.ReadByte()
     at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
     at System.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK)
     at System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject, Boolean withFailover)
     at System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart)
     at System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance)
     at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance)
     at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection)
     at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup)
     at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)
     at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
     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()
  </code></pre>
  
  <p><strong>NOTE</strong> <strong>I have tried</strong> </p>
  
  <ul>
  <li><p>closing, reopening Sql server Management Studio.</p></li>
  <li><p>closing , reopen VS &amp; rebuild Solution</p></li>
  <li><p>killed worker process accessing database.</p></li>
  <li><p>login credentials are correct.</p></li>
  <li><p>able to ping server to make sure its not down.</p></li>
  </ul>