This is a technical problem that is only occurring on specific tumble dryer models.
Empty the condensate container as indicated in the tumble dryer’s display and ignore the message in the app.
The Miele app is displaying the wrong message when the tumble dryer’s condensate container is full. The message Empty container should appear in the tumble dryer display when the condensate container reaches its maximum level. However, the Miele app is displaying the message Your appliance is reporting an unknown fault.
Empty the condensate container as indicated in the tumble dryer’s display and ignore the message in the app.