SQL 2016 - SSRS - Error 503

After setting up SQL Server 2016 Reporting Services, you cannot connect to the new SSRS 2016 Web Portal.   For the the June 1, 2016 General Availability (GA) release, the URL is http://[ComputerName]/reports.

We had issues with the pre-release versions, and with the initial setup of SSRS, we still have an occasional Error 503.

After stopping, and restarting the SSRS service using the SS Configuration Manager, we were able to connect to the new SSRS service.