The thread could be jamming due to several reasons.

• Make sure the needle is correctly inserted with the flat side facing the back and pushed up into the machine as far as possible.
  
  
• Needle is incorrect. Be sure to use the embroidery needle(s).
  
  
• The needle is not at the correct position.
  Touch the key to move the desired needle bar to be threaded into embroidering position.
  
  
• The hook on the automatic needle-threading mechanism is bent. Consult nearest authorized Dealer or Service Center.