Gateway - problems on retreiving data from SSAS2012

[Anto]

I have problems with the reports published in Power Bi which are using a live connection to SSAS Tabular on premise data source.

I have already installed the gateway Power BI Gateway – Enterprise and I added my SSAS Tabular as data source under the enterprise gateway (the test was OK). I added my user to the users’ list (as user with permission to publish reports and using the datasource), the same user was added in a Role of SSAS Tabular.

Can someone please guide me on how to set up the gateway?

Is it necessary to do something else in order to see the data in the report? Because when I attempt to view the published report I receive the error "Data source access error.  Please contact the gateway administrator." 

[cryan]

That's the error I was receiving last week, before installing the latest version of the gateway. It seems the preview gateway I installed in December may have had the option to select an SSAS data source, but I think some components may have been missing. Downloading the latest and greatest resolved my issues. The two installers also had a pretty noticeable difference in size.  

There are log files where you may find the error. Mine was that some ADOMD components were missing.

C:\Users\PBIEgwService\AppData\Local\Microsoft\Power BI Enterprise Gateway\EnterpriseGatewayXX.log

Another piece I've found with the SSAS connections is that UPN on the user's AD account matters. That's where the lookup is taking place between powerbi.com and AD. In my case, my PowerBI account was cryan@biz.com and the UPN attribute I had in AD was cryan@bizcorp.local. Changing the UPN to cryan@biz.com allowed for the lookup to take place, the account to resolve within AD, and for the credentials to be passed along to SSAS.