This message is displayed when the bobbin thread is running out.
Although a few stitches can be embroidered when the [Start/Stop] button is pressed, replace with a wound bobbin immediately.

When embroidering, press  , press [OK] , remove the embroidery frame, and then replace the bobbin with one wound with plenty of embroidery bobbin thread.
 

If [Upper and Bobbin Thread Sensor] in the general settings screen of the machine setting mode is set to [OFF], this message does not appear.