Oil level sensors don't last forever. They have a float inside that has to move freely to give an accurate reading. Over time the float deteriorates and the float chamber gets filled with muck and varnish (the same stuff you're draining out during an oil change), and begins to bind up or gets stuck. As you drive around, the oil sloshes around in the pan, especially when going around turns or going up or down hills. If the float binds up, you'll get an error.

Change the sensor/sender at your next oil change. The pan has to be empty or you'll get covered with oil.