Possible Causes

Faulty Candy door interlock switch, Misaligned door latch, Broken door catch, Wiring fault between door lock and control board

How to Fix / Troubleshooting

Safety first: Unplug the dishwasher before working on the door assembly.

Check door closure: Ensure the door closes firmly and is not obstructed by dishes or the lower basket.
Inspect latch and strike: Open the door and examine the metal or plastic strike on the cabinet and the latch mechanism in the door. Look for wear, cracks, or misalignment.
Test door switch: With the inner door panel removed, locate the door interlock. Check that the actuator moves freely when the door is closed. If you have a multimeter, test continuity across the switch when engaged.
Adjust or replace: If the strike is misaligned, gently adjust its position. If the switch is faulty or the latch is broken, replace the door lock assembly with the correct Candy spare.
Check wiring: Inspect the harness from the door lock to the control board for damage, especially where it passes through the door hinge area.