Even since an update in late September 2019, I have not been able to consistently launch Don't Starve Together. When I click on the game, it loads it, but no screen comes up. Steam says the game is running, but won't open the game. When you click on Play Game, it says the game is already launched. I have to keep forcing the program to close; if I am lucky, the game works the second time around.
I have checked the integrity of the files (they are fine), I have uninstalled the game, and I have uninstalled Steam multiple times. Whatever this latest update is, even reinstalling Steam has not worked.
Click on the Steam app, allow it to check for updates, login, try to launch DST.