Increasingly more frequent, I get the following error when trying to join a server:
Connection to the game server has been lost
Referred to as "Connection Lost". Has anybody else got the same problem?

I don't really need solutions: a (few) restart(s) of the game is usually enough to get it going, and once it's going, another few hours of my life are gone. It's not my router or any of the settings that usually cause the problem: in the close to 290 hours of lag-less play I've had so far, I never encountered the problem.