First of all, Remove all the cartridges, turn off the machine, disconnect both usb cable and power cord from the unit, wait for few minutes (10 mins), reconnect the power cord, again turn back on the printer, reinstall all the cartridges, check the status once again and if the problem persists, try to check for broken pieces of or other foreign particles like thread or hair. You'll need to pull out both the front and the rear tray (Input and output tray), look carefully and if possible use a blower to blow through the passage, from top to front or from front to top. Once again, turn off the machine and turn back on and check the status. If the problem persists follow the instructions here
(click here).
Please do this slowly and make sure you wait as mentioned above. Even if you don't see actual paper, something might have been interrupted the sensor, it'll be cleared after few attempts.
Let me know if you still have the issue.
Good luck.
Thanks for using
FixYa.