There are some errors while compiling without the solution file. First: non existing member of the volatile structures of U Error 'volatile struct <anonymous>' has no member named 'TRCPT' at 9dof_bootloader_sparkfun\board_driver_usb.c 176 52 Build Error 'volatile struct <anonymous>' has no member named 'STALLRQ' \9dof_bootloader_sparkfun\board_driver_usb.c 307 51 Build Both of them are located in USB_DEVICE_EPINTFLAG_Type struct in usb.h. But the compiler could not find. Furthermore, could you guide me how to correctly compile this in Atmel studio?