Hi Enrique_TE,
I go through your post carefully and as per your description, I'd like to confirm from what data source you encounter the issue? Does the issue happen when you get and load some data from some specific sources?
Meanwhile, upload a full screenshot of the Account page in the Excel application you are using for our reference. You can access the page via clicking on File>Account.
Note: Remove any private information before uploading the screenshots.
If you don’t mind for test purpose, do on other computers with the same version number of the Office applications to see if the issue happens in your environment as well.
Meanwhile, I would suggest you check methods from the thread: "PowerPivot is unable to load the Data Model" in Excel 2016 and Windows 10
- close the xlsx in question
- open the xlsx with favorite zip tool (i used 7zip)
- delete the "/xl/model" folder
- open xlsx with Excel again and respond to prompts that Excel needs to make repairs to the file
- and that was it
I appreciate your patience and understanding.
Best Regards
Waqas Muhammad