Some users have found that when they start Slender and click Play, the screen fades to black and then the game crashes. This is usually because you don’t have Unity Web Player installed.
Unity Web Player is a plug-in that allows you to play games developed with the Unity engine. It’s an alternative to Flash Player although unlike Flash, its dedicated specifically to gaming.
Unity Web Player is available for both Windows and Mac and takes just seconds to install with an installation wizard to take you through the process. Once installed, it opens up a whole world of gaming options such as 1916, Battlestar Galactica, and Basket Dudes.