Unable to create Shared Data Source

Hi,

I installed SQL Server 2016 RC3 with Reporting Services (native mode) in Windows Server 2012 R2. When I try to create a shared Data Source in the "Web Portal" it gives me the error "Something went wrong. Please try again later." and the "New Data Source" has all the editors disabled with the error box saying "The data extension used here is not available. It has either been uninstalled, or it is not configured correctly."

What did I miss?

Thank you,

Dmitriy