Delonghi Magnifica des not complete descalcification function

I performed the descalcification process several times before, without a problem. This last time something happened.

The first step of the process is to clean the machine with a product that removes calcium from the pipes. That performed well. But on the second step, when you do the same thing just with water, the process comes into a cycle where I keep filling the water dispenser and the machine keeps circulating water. I'm always waiting for the "out of water" light to come on, but it never does. When the machine runs out of water, the pump keeps operating for a few seconds until it stops. I put more water, but the sequence keeps repeating. Any ideas?