You should try reinstalling DirectX like X-Brandy-X suggested, but if that doesn't work, you could attempt switching your rendering engine to OpenGL. Navigate to C:\FeralHeart (default install directory on Windows) and open ogre.cfg with a program like Notepad or Wordpad. At the top there will be a line that says Render System=Direct3D9 Rendering Subsystem. Change the part that says "Direct3D9 Rendering Subsystem" to "OpenGL Rendering Subsystem" so the line says Render System=OpenGL Rendering Subsystem and then save the file, close the file, then try to launch the game. Good luck. ^^
