External Data Refresh Failed - Windows Authentication and user credentials could not be delegated.

[k58486]

The error message is :  

"The data connection uses Windows Authentication and user credentials could not be delegated. The following connections failed to refresh: "

Users get this message whenever they try to connect to an SSAS tabular Model from an Excel workbook hosted on our Power BI Report Server.

Has anyone seen this before? Help!

[d_gosbell · Accepted solution]

If you are rendering the Excel files in the portal this would mean that you have the Office Online Server integration enabled Host Excel workbooks using Office Online Server (OOS) - Power BI Report Server - Power BI | Microsof... and the error most likely indicates that you do not have Kerberos correctly configured. This is not a topic I know much about myself, but I did find the following articel Data authentication for Excel Online in Office Online Server - Office Online Server | Microsoft Lear... and the following might also be helpful Configure Analysis Services and Kerberos Constrained Delegation (KCD) | Microsoft Learn