Power BI - SSAS Tabular Connection Issue

[pbix]

Hi, 

I'm after a little help. I have a Power BI report connected LIVE (not imported) to an instance of SSAS Tabular 2016 which sits on a server in Domain A. 

However, we are currently migrating our users to a new domain - lets call it Domain B. 

Users who have not been migrated to Domain A can still access the report / data from SSAS Tabular.

However, users who have been migrated to Domain B can no longer access the report - they receive the following error message:

This report couldn't access the data source - contact the administrator to have it fixed. 

Couldn't load the schema for the database model - make sure you have a connection to the server etc...

Activity IDfd2e6ea4-5fb6-4920-b17c-dcf37d7be088

Request IDb375c25f-02b2-843b-063b-474b7a783afa

Correlation ID930020ed-6234-5da3-aeb2-7eb81313f711

I presume this is an issue with user principal names however, I have done the following and am unable to bring the report back available for users on Domain B.

I have

added 'Domain B\All users' AD Group to the read role in tHe cube

change the user principal name from Domain B to Domain A in the Power BI Data Source Mapping Page

Republishing the pbix file (data is available in the pbix file OK)

I'm not sure what else to try - could anyone offer any additional insight?

Mods - how do I get the error message associated with the correlation ID?

Thanks, 

pbix

[GilbertQ]

Hi there

What you would need to do is to go into the Manage Gateways, then click on the SSAS Source.
Then click on Users, then click Map Users
Then you would need to map your users who are looking in to your cube with the expected domain, which should hopefully work as an interim measure.

[pbix]

Thanks @GilbertQ

Hmmm.... OK, so I just re-mapped usernames again - but unfortunately it had no effect - e.g. returned the same error message.

However, I just thought I'd see what happens if I change the user mapping type to 'Custom Data' (and remvoed the user mapping converion from Domain B >Domain A) - and 5 minutes later it appears to now be working for me - though I haven't yet tested for other staff.

What does the 'custom data' feature do in the user mapping pane?

Thanks,

pbix

[GilbertQ · Accepted solution]

Hi there

What it will do is to pass the Custom Data through to the underlying SSAS Tabular instance. Which in your instance it appears due to the current configuration it is passing credentials which it can then validate on the SSAS Tabular Instance.

[pbix]

Thanks @GilbertQ. 

I wish Poewr BI was a little bit more transparent about how it handles certain elements about itself but as it now works with 'custom data' enabled then I'm happy eough!

Thanks again 🙂

[GilbertQ]

Glad to hear it is working!