What does the red triangle on a De'Longhi Magnifica actually mean?

For me the brew unit was extremely caked with grounds from previous owner who apparently did not clean it out regularly. Once cleaned out and lubricated the machine, the triangle warning light went away. These machines need to be maintained more often than the manual states.

Weekly is alot. I do mine once a month.
 
Yes, the position sensor on the brew motor can fail. I had one of these machines fail due to this and replaced the sensor for around $12. Works great now. Have to take the side panel off the machine to reach this though.