The screen says "bed mapping error"

This is likely the result of the extruder cable cord not being fully plugged into the extruder. Unplug and plug the cord back in, securing it firmly into the port. The end of the cord should dip slightly below the top of the extruder and lock into place. 

Be sure to have the extruder itself all the way down and locked into the horizontal beam--if the extruder hasn't slid into the socket all the way, these error messages are likely to show.

While your at it, double check all cords are fastened into their plugs. Make sure there is nothing on the bed itself. Remove any masking tape on the bed if you've put down a later, as it may interfere with the mapping process.

If you're still having trouble, you can try doing a factory reset. Then reach out to [e-mail] if that doesn't resolve your issue!