Impersonate Users for Security Role Performance testing

[MattKarriker2]

I have a case where a user is unable to execute a specific report.  Other users have no issues executing the report.  The difference between the users are their assigned roles in Power BI dataset.  I am looking for a way to impersonate the user having the issue to further isolate the issue.  

Our environment is Power BI Premium.  We have a XML read/write end point in place and normally use SSMS and DAX Studio to test performance.  Both SSMS and DAX Studio have the EffectiveUserName parameter available which historically has been used for impersonation in SSAS.   For some reason both SSMS and DAX Studio throw the below error when I use the EffectiveUserName in the connection string.  Has anyone been able to use EffectiveUserName property of the connection string using DAX Studio to troubleshoot security role performance issues?

The '<pii>xxxxx@xxxxx.net</pii>' value of the 'EffectiveUserName' XML for Analysis property is not valid.

[Greg_Deckler]

@MattKarriker2 In the Service, find the Dataset, click the ellipses and go to Security. Hover over a role, click the ellipses and choose Test as role.

[MattKarriker2]

@Greg_Deckler This is a step we have completed.  The report runs as expected.  But still the users are not able to execute the report in service.  

[Greg_Deckler]

@MattKarriker2 Is there an error or do they just not see anything? If they don't see anything, try having the user use the "Reset to default" in the Service.