The "SSIS801" error in SQL Server Integration Services (SSIS) typically occurs when there is a between the SQL Server Native Client installed on your machine and the SQL Server instance you are connecting to. The mention of "4K" (or "4k") might refer to version 18.10.x (OCT) of the SQL Native Client (18.xx.x), which is part of the SQL Server 2022 ecosystem. Below is a breakdown of the issue and how to resolve it: What is the SSIS801 Error? The SSIS801 error is a generic SSIS exception that occurs when there is a problem with the SSIS runtime environment , SQL Server Native Client , or ODBC/OLEDB drivers . The error message often looks like this: