Possible cause:
The line may be broken or out.
To remove the TRIMMER HEAD, press the sides and turn it to release it.
Use line size: 0.095 in. and max length of 14'.
You may use any local hardware store lines.
Insert the line through the eyelet of the spool and feed it through the other side. Ensure both ends of the line are even (approximately 7 ft. each side).
Put the spool back into the TRIMMER HEAD (11). It may take a few seconds to adjust the spool back in. Once it is secure in the TRIMMER HEAD (11), ensure that the line is even on both sides.
You will hear it click back in place.