In some rare cases, your game may fail to shut down fully when you close it out. This will cause Medal to think that your game is still open.

How to end the game process

Open Task Manager and click on More Details if you have the small window view
In most cases, the game may still be running in the Background Processes section. Locate any processes linked to your game and select End Task

I can't find the game process

If you cannot find the processes in Task Manager, the other method is to restart your PC. Restarting your PC will clear your systems cache and generally help Windows perform better.