Yeah, this one's common and usually points to the crisper plate or basket. The clicking is likely metal-on-metal contact from something not seated right.
- Turn the unit off and unplug it. Let it cool completely.
- Remove both baskets. Take out the crisper plates.
- Reinstall each crisper plate, making sure it's flat and fully seated in the bottom of its basket. There shouldn't be any wobble.
- Slide the baskets back into the main unit until they click into place. They must be properly closed before operating.
IF THAT DIDN'T WORK: The noise could be food debris hitting the heating elements. Always ensure the basket is properly closed and never overfill. Overfilling can cause food contact with the heating elements. Shake the basket during cooking to redistribute food and prevent pieces from getting stuck.
HEADS UP: If the unit ever emits black smoke, unplug it immediately. Wait for smoking to stop before removing the baskets.