Your printer suspects that everything is not in perfect order with your end-stops.
Make sure there is not a wiring-issue with the X/Y end-stop on the mini RAMBo board.
Go to the LCD menu -> Calibration -> Show End stops. Once you are in this menu, manually click on the X/Y End-stops one by one. During this procedure, monitor if there is an appropriate change on the LCD.
More common is that the X/Y End-stops were not installed correctly during the assembly.
The easiest way to check that is by doing the following:
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