Game already running issue

I pressed the green Start button to start the game in Steam; it showed the Easy Anti-Cheat launcher panel. After a while, the start shut down and show me the game was already running. I tried to close the game through Task Manager and restarted my PC, but it didn't work. I also tried to start it from the .exe file or verify the integrity of Game Files from Steam. But they also didn't work. How can I fix it?