I have a Window 8 tablet and I can’t launch a game with the Direct3D or opengl drivers unless I connect a mouse to it. SDL works. Here’s relevant log bit:
RetroArch: Graphics driver did not initialize an input driver. Attempting to pick a suitable driver. RetroArch [ERROR] :: Cannot init input driver. Exiting … RetroArch [ERROR] :: Fatal error received in: “init_video_input()”