PowerBI API Usage - Sample app - UserNotLicensed

Question

Hi, I have a working PowerBI Public Preview account.
I'm trying to use the PowerBI RestAPI but keep getting "User is not licensed" (the sample app is here: https://msdn.microsoft.com/en-US/library/dn931282.aspx#Configure)
The user is provisioned correctly in Azure Active Directory, as specified by the link above. What am I missing? Do
I need to change the baseURI in the PowerBIModel for the sample app? (see below). 
C# code (line 19 in PowerBIModel.cs in the SampleApp
static Uri baseAddress = new Uri("https://api.powerbi.com/beta/myorg/");I have tried replacing "/beta/myorg" with "myADName.onmicrosoft.com/myAppName"
as suggested here: https://msdn.microsoft.com/en-us/library/dn877544.aspx
but I arbitrarily get either "UserNotLicensed" or "Invalid JWT token" 
Thank you for any help you can offer.

Answer 1

In case anyone else keeps getting the same error ...
I think It was caused by a simple cookie issue as follows....just use a different browser & clear cookies/cache if you are testing with >1 PowerBI account....and make sure to use an AzureAD user you created within AD, not your generic Azure acct.
I was signed into "Account1", which was not part of my AzureAD...but it had a PowerBI subscription. 
When I ran my webapp on localhost, it asked me to sign in to PowerBI via Oauth. So I signed in using [AzureAD member acct] "Account2". (or it just signed me in directly..probably to Account1)
It kept trying to use Account1 to authenticate...as the issue disappeared when I switched browsers and cleared cookies in the new browser. Occasionally I also
got the message "Request headers too long"....for the same dual account reason..same fix.