Water leak from kitchenaid fridge. Thermistor broken?

my kitchenaid fridge builds up water at the bottom of the fridge. It then freezes over and more builds up until it leaks out of the fridge. I checked the drain and it is not clogged - water will drain. I think it may have something to do with my thermistor. The fan works fine. I have no idea why my fridge builds up water. It usually takes 3 months to build up and freEze over at the bottom of the fridge.

Please see pictures. Do I need to replace?