Toner error

Remove the left. panel on the machine. there is a screw in front and back. Once off near the front there is the mechanism that the front door actuates when closing. Near that there is a lever that sticks out into the area inside where the cartridge goes into the machine. This also can be see looking into the front of the machine on the left side the is a small black actuator that should move freely. It is jammed and popped out. Pop it back into place by pushing it back in gently from the side. This will fix your issue. Reassemble :)

Good luck and let me know if you need help!