Diagnosis
The scanner carriage is getting stuck. A piece of debris, a warped document, or a failed calibration can cause the scanner unit to hit its limit and error out.
How to Fix It
Unplug the printer. Manually move the scanner carriage (the part under the glass that has the light bar) from side to side by gently pushing it. It should move smoothly. Check the white plastic scanner rail on the left side for any obstructions or sticky residue. Clean the rail with a dry cloth. Plug the printer back in and turn it on. The scanner should auto-home, which might fix it.
If That Didn't Work
The scanner might need a mechanical reset. With the printer on, open and close the scanner lid (the document cover) 5-10 times in a row. Sometimes this jogs the internal sensor. If that fails, there's a scanner reset in the service menu, but accessing that is tricky and not recommended casually.
Heads Up
That clunking is the carriage hitting a physical stop. Don't keep trying to scan from software if you hear it, as you can damage the drive belt or motor. Address the physical obstruction first.