if u run into any issues with the may update it realy doesnt like any usb disk drives attached of any kind so bare in mind if using the ryujin to disable its drive in device manager before starting the upgrade or it will fail
i think the problem ppl are having was adressed before but put basicly u probly chose notepad or some other text viewer to read your result , resulting in a .text file instead of the rbr i made the same mistake too