it was my experience two weeks ago, when Report Server was only displaying down to the orange/blue line, no admin controls, no menus. Restarting the services corrected the first problem. The DB had been stepped on, and a restore was required; but, nothing below the line was visible until the services were restarted. SSRS certainly is not the best product, and it is Microsoft. Not restarting, in most circumstances, is foolish.
Any Cloud, Any Database, Oracle since 1982