As insane as it sounds, there are users that just LOVE clicking our “app.exe” as fast as possible which results in many app windows opening. If they launch the app, let it load, and then try to launch a second instance then Unity is able to prevent multiple instances. Does anyone have a good idea on how to prevent multiple app launches other then issuing users very hard the left click mice?
Open a file in a known location with exclusive write permissions. If that fails, exit, as another instance of your application is already running.