The bug

If you have the setting that keeps the launcher open while games are running, the "Game already running" prompt won't close after clicking "Start anyway". You need to click "Cancel" to continue using the launcher.

Along with inconvenience, this may lead to users accidentally starting the game multiple times within a short time. For example, a user may think that the launcher is unresponsive when the prompt doesn't close and keeps clicking the button, lagging the computer along with opening too many game windows.