This indicates the drain pump filter located on the bottom front of your appliance is clogged, and you have to clean it.
Please try this to solve the issue:
You will have to unplug the appliance and remove the bottom front flap.
Then keep some beach towels and shallow container under the filter.
Now, rotate the drain pump filter anti clockwise to open, clean it completely and make sure it is not clogged.
Also with your fingers check if impeller rotates, then reconnect everything and plug it back.
Then try an empty program on its hottest setting, and it should work however, if the issue appears again, then I am afraid, the drain pump is faulty, and will need replacement.
Alternatively, you may call De Dietrich at 0330(###) ###-####to book repair.
If there is anything else I can help you with, please let me know.