Issues connecting to On-Prem Tabular Model

All, 

After 1 month and 2 days, we finally got to the bottom of the issue. 

I opened a ticket with Microsoft to troubleshoot the issue. The engineer I was working with worked on comparing outputs of whoami /all across different users (the ones experiencing the issues vs. the ones not experiencing the issue) to see what kind of membership at the domain level one user had that the other didn't. Unfortunatelly, we did not get anywhere with this approach. 

The Engineer then brought someone from Directory Services into the issue. The DS Engineer requested us to add the “Authenticated Users” group to the “Pre-Windows 2000 Compatible Access” group and like magic, users were able to access data on-premises from PowerBI.com. 

After the above was done, I introduced two new users to the equation by:

• Assigning user a PowerBI Pro account
• Added user to the Data Management Gateway group on the machine where the Data Management Gateway service is running
• Added user to Read Role on SSAS
• Shared a test dashboard connecting to SSAS on on-premises with the two users

The users are now in business. We can now roll this out to production.

Is anyone from Microsoft watching this forum? Is the above documented anywhere? If not, this should be documented somewhere. 

Anonymous Bjoern