The printer is showing the message: "Failed to home the extruder in Z-axis, make sure the loadcell is working".
Error name: Homing error Z
Error code: Z #13301 (MK4) Z #21301 (MK3.9)
A fault in the loadcell can trigger a homing error. Ensure that the printer is fully cooled down, go to LCD Menu - Calibration - Diagnostics - Loadcell Test, and follow the instructions on the display.
During the test, see if the numbers shown on the screen will change. In case the number does not change when you tap the nozzle, please contact our customer support.