So you're not launching it from the Steam Client, but directly launching rFactor.exe, fair enough. I could tell you that technically it will reach out to the Steam Client anyway, because of the Steam integration and for DRM checks, so it really makes little difference, but that won't solve your problem. Steam overlay is something different from the client. You probably have seen it, but it really is an overlay over your application. Disabling it is what Steam recommends in case of problems, which is why I'm asking. You can disable it in the Steam Client. Please try that. And also try the "trace=3" and post the output here. Just stating it does nothing does not help me diagnose the problem (as I cannot reproduce your issue on my system).