USB interface is detected, that's good. Install u-boot.bin.sd.bin via BootcardMaker (see method 3), insert the SDcard into the card slot of the box and start it again.
where I can get a uboot file for a M8s Pro L (lq version)
I have the problem that I cant flash the box via Usb Burning tool. It always stops at 2% and give me the romcode error. Tried everything but nothing works..