Unsupported file formats

As of April 2022, we no longer support the following file formats for use as a DataFlow template:

.XLS - The Excel 97 - Excel 2003 Binary file format (BIFF8)
.XLSB - The binary file format (BIFF12) for Excel 2010 and Excel 2007

These formats were the primary formats stored by Microsoft Excel up through Excel 2010 and replaced by XLSX and XLSM. DataFlow will continue to support the XLSX and XLSM file formats.

Although Microsoft Excel continues to provide open and save capabilities for these formats, performance characteristics of modern systems, including DataFlow, do not permit the appropriate user experience required by enterprise systems. These file formats may continue to function within DataFlow, and will not be blocked, but some functionality may perform poorly or not at all when used. Should an issue be encountered while utilizing the XLS or XLSB file format, please use Excel’s “Save As” or “Save a Copy” to save the file in XLSX or XLSM format and try again.

File formats that are supported in Excel (microsoft.com).