Login timeout expired A network-related or instance-specific error has occurred while establishing a connection to SQL Server. Server is not found or not accessible. Check if instance name is correct and if SQL Server is configured to allow remote connections. For more information see SQL Server Books Online. TCP Provider: 連線嘗試失敗，因為連線對象有一段時間並未正確回應，或是連線建立失敗，因為連線的主機無法回應。