Baby egg not moving inside

Hey guys is Erika here!, I have a 2 year old mama hen that has been siting on eggs before! And this year we discussed to have more baby's so when have three fertile eggs and two hatched and now mama hen is still sitting on the third egg still and hopping in and out of the nest and I keep putting her back in for her to sit on the egg!, well I candled the egg and I see NO movement but it's almost full! Idk what happened but do u think the chick is died, and there is no moving in the egg , I heard no kicking, and no heart beat. So does anyone know what's wrong??