Latest firmware update has stopped Z-Axis working
I've just applied the latest firmware update (3.9.1) to my MK3 printer and after the update was applied I was unable to move the X-Axis. I decided to start from scratch and do a complete calibration again and all seemed to go well but the main screen shows the Z-Axis at -536970. When I try to move it, it goes straight to +0.0 and the z-axis tries to drive up past it's upper limits and just jams at the top. I've since done the calibration procedure twice more but still no luck. I can't see anything that's changed from my last print.