If the bobbin winding starts when the thread is not passed through the pretension disk correctly, the thread may become tangled beneath the bobbin winder seat.
Wind off the thread according to the following procedure.
Touch [Stop] once to stop the bobbin winding.
Cut the thread with scissors near the pretension disk.
Push the bobbin winding switch to the right, and then remove the bobbin from the shaft and cut the thread leading to the bobbin in order to be able to completely remove the bobbin from shaft.
Hold the thread end with your left hand, and wind off the thread clockwise from under the bobbin winder seat with your right hand as shown below.