I restarted my SSRS 2016 server. When I navigate to the Web Portal URL I get a "Service Unavailable - HTTP Error 503. The service is unavailable." message. How do I start the SSRS 2016 Report Server?
I found the solution. There is a "SQL Server Reporting Services (MSSQLSERVER)" service that manages, executes, renders, schedules and delivers reports. It was set with an "Automatic" Startup Type. After a reboot the service was indeed running but I was still getting a 503 Service unavailable error. I found a blog that says the Startup Type needs to be "Automatic (Delayed Start)". Once I changed the Startup Type to "Automatic (Delayed Start)" and restarted the service the report server started working.