[2020] R6 won't lauch

Just a few days ago the game was lauching and working fine. Now when I go to lauch it a message from steam pops up saying "Preparing to Launch Rainbow Six Siege" and then goes away a few seconds later and nothing happens. I can't get on to the game or onto uplay. I've tried veriying the files, reinstalling the game, and putting the game into compatability mode. Nothing has worked. Does anyone know how to fix this.