DIAGNOSIS One of the drive wheels is stuck or not making proper contact with the floor, causing a traction error.
FIX Pick up the robot and inspect both large drive wheels. Pull off any wrapped hair or debris. Manually spin each wheel; they should rotate freely and spring back when pulled. Clean the wheel treads with a dry cloth.
IF THAT DIDN'T WORK The issue could be a failed wheel encoder. Listen for a faint, rapid clicking sound from one wheel when it spins. If you hear it, that wheel module likely needs replacement.
HEADS UP High-pile rugs or very slippery floors can also cause this. If it only happens in one spot, it's an environmental issue, not a robot fault.