The drain filter has not been screwed tight or has been screwed in cross threaded.
The drain filter and the drain pump are blocked.
Clean the drain filter and the drain pump:
Switch off the washing machine.
Open the access panel for the drain pump.
Place a suitable container under the access panel, e.g. a universal tray.
Slowly unscrew the drain filters to let the water out.
To interrupt the flow of water, tighten the drain filters back up again.
If water stops flowing out, unscrew the drain filters completely.
Clean the drain filters thoroughly.
Check whether the drain pump impellers can rotate freely. If necessary, remove any foreign objects (e.g. buttons, coins) and clean the interior.
Put the drain filters back in place. Please note that each drain filter must be inserted on the correct side.
Screw the drain filters tight.
Close the access panel for the drain pump.
If the fault persists, please contact Miele Customer Service or book a repair appointment online.