NSF disabled

Please advise as to why I get the following email message almost every day my kids are on. Doesn't matter which child is on it seems:

 

Norton Safety Minder on KIDS PC used by xxxx has been disabled. Therefore, Norton™ Online Family cannot monitor the Internet activities of your children. Go to your child's computer and restart Norton Safety Minder.

 

Any direction here would be greatly appreciated!!

Arron