The object was printed and Zortrax was ready for the next job.
A new spool of filament was to be fed into the extruder, when I heard this clicking and saw the wheel on the motor stop and move and stop again.
Thought that old filament was stuck between the wheel and the ball bearing.
Fed the new filament, but as soon as I started to move the filament down, the clicking increased.
Touched the ribbon cable and clicking increased again.
Replaced the ribbon cable and Zortrax works fine now.
2 200h since last replacement of ribbon cable.