If you need help, we need to know what rom your trying to run, and system specs. The error your getting can be due to using the wrong plugin or a unsupported uCode (game not supported). As F-3582 noted, your best bet is Jabo's Direct3D 6 or 7 (works with OpenGL cards), as they are the most compatable, and most of all look at the rom browser, does it say its playable?