Yes, restart is the only solution sometimes. And pictures are speaking a thousand words here…
SSMS has been keeping very busy lately, for hours !
Object Explorer does not recognize Start, Stop, etc – for the time being !
SSMS runs out of steam, tired of being busy, though there is enough available memory on the box.
Last but the not the least: Configuration Manager’s TRY/CATCH comes into play.
Services.msc? same as Object Explorer: cant start, stop or pause SQL service.
Solution: Start -> Restart !