DIAGNOSIS The Drip Stop lever (the red switch on the front) is mechanically stuck or its sensor is blocked by coffee grime.
FIX Manually exercise the lever and clean the slot. Turn the brewer off and unplug it. Move the red Drip Stop lever up and down firmly 10-15 times. Use a damp paper towel to wipe inside the slot where the lever moves, then use a dry Q-tip to absorb any moisture. Plug the brewer back in and turn it on. The error should clear.
IF THAT DIDN'T WORK Coffee grounds or a small object may be physically jamming the mechanism inside. Remove the water reservoir and look down into the opening where the Drip Stop lever connects internally. Use a flashlight and tweezers to remove any visible debris.
HEADS UP This error triggers automatically after 30 brew cycles as a reminder. You can clear it temporarily by manually cycling the lever, but you should run a full CLEAN cycle (with the cleaning pod or vinegar) to reset the internal counter and prevent it from recurring.