I updated my firmware using the supplied hex file for the Robo R2 using this download -Marlin_1.1.6_RoboVersion_1.2.4_R2.hex. After using it, it told me to set the z height so i followed online instructions. When I selected the top right z height wizard button, it said it would take some time but it is not working. I have left it for probably more than an hour with no success. Tried the firmware file Marlin_1.1.6_RoboVersion_1.2.4_R2.hex with same results. Any help would be appreciated.