A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Hi BittnerT,
“Initialization of the data source failed” error message can occur if you are opening a newer Data Model in an older version of the Power Pivot add-in.
As an initial troubleshooting, we suggest performing a Safe Mode in your Excel 2016 application and see if the error will still appear.
Check this article to open Excel in safe mode on your Windows PC.
Keep us in the loop with the result.