Unable to connect to SSAS Tabular from Service

[Anonymous]

Hi All

I have a PowerBI report that is using a SSSAS Tabular model as as a data source, using direct query. The Tabular model is on premises and we have an on-premises gateway setup. I have deployed the report to the PowerBI Service. The report has been refreshing in the PowerBI Service fine for a week until a couple days ago, but we are now getting the following error.  

“The report couldn’t access the data source because it doesn’t have permission. Choose another data gateway or contract the gateway administrator”.

All of the other developers in my team  are getting the same error. End Users who try to access the report via the PBI service are getting a “Couldn’t load the model Schema”.

We have tried the following

• Re- adding our credentials to the on-premises gateway. This doesn’t resolve the error.
• Deleting the Tabular model and redeploying it. This temporarily resolved the issue. We assumed the original Tabular model had corrupted. However, the issue returned an hour or so later.

Other observations

We can connect to the Tabular model from the PBI Desktop fine (also with SSMS). The error only occurs when the Report is in the service.

To me the error is feeling like it feels like an issue with the PBI Service because :

1. Report was working fine for about a week before the error occurred.
2. The error is affecting all developers and users of the report (so it doesn't appear to be an isolated credentials issue.
3. The report works fine in the desktop

Yesterday I saw another post on the PBI Service Forum titled “Unable to connect to SSAS Tabular from Service” that may be related.  They were using Azure Analysis Service (rather than the on-premises model we are using), and reported a similar issue that they described as: 

 “Power BI desktop connect well to the Azure Analysis service but not from Power BI Service. Below are the error details- Couldn't load the schema for the database model…”

 That thread had 16 replies, but no solution (other than a members suggestion to raise a ticket with Microsoft).

Can anyone suggest a way forward,  or has experienced a similar issue and managed to resolve it?

Thanks Steve

[Anonymous]

Hey Steve.  Sounds like a different issue to the other thread.  That issue looked to be a problem with 2 different account domains passing security between themselves.

Your one appears to work for a period of time then stop working.  It would seem to me that if you work out what circumstances cause this temporary fix then perhaps the cause will become clear.  Something I would first look into is what User/Pass are you using with the gateway and could that have any changes.  For example in some occasions a username might be assigned as authentication but then the password gets changed. The stored password then fails.

[Anonymous · Accepted solution]

We deleted the users from the gateway, and re-added them. Then the  issue went away. Interesting that the problem occurred following a team wide reseting of passwords. Seems like the updated paswords didn't propogate to the Data Gateway. 

[Anonymous]

The gateways will remember what password you stored against the user credentials and should check them against the current password in AD.  If there is an update, the stored credentials will mismatch from the newly updated passwords in AD.

I'd recommend making use of service accounts with non-rotating passwords if possible.