I'm guessing as you did not list the model number. Something similar happened on mine. Due to a freeze, there was a small crack in the inlet and water had slowly leaked. As a safety feature, the Asko has a tray under the dishwasher inside the overall dimensions. It has a float. When the float rises, the drain pump starts and the dishwasher will not start. In my case, the drip pan is not connected to the drain which gave me the drain sound, but did nothing to remove the leaky water.

I suggest you take the front bottom panel off the dishwasher and check for water/leaks.