PRINT FAN ERROR error message occurs when the print fan (the one at the front of the extruder) does not receive any RPM (Revolutions per Minute) readings. This can be caused by the fact that the fan does not spin, or by the signal (yellow) cable being interrupted.
Visually inspect the print fan and make sure there is no debris or pieces of filament tangled in it, preventing it from spinning. Bigger parts can be cleared with tweezers, dust can be cleared with a computer cleaner spray (canned air).
If the error shows up even after cleaning the fan, see if it could be reproduced, by starting the fan from Settings -> Temperature -> Fan speed -> 255, and then moving the extruder manually along the X-axis, to the right and to the left multiple times.
See if the fan at any time stops spinning. Also, check the cables and wiggle with the extruder cable bundle a bit. The culprit is usually within the harness, near the extruder body.