None of the eggs are hatching?

Hey, i have nine hens and one Silkie rooster. I don't know his age, stupid i know :/
I've a one year old Marans and a five year old Oprington hatching eggs. I candled all their eggs ( 16 ) ( My oprington is a big girl and a bit of a hoarder) and not one of the eggs will hatch. My Silkie rooster still goes after the hens, and fathered chicks two years ago to another Silkie hen ( unfortunately her two chicks were crushed and she died herself a few months ago to unknown causes)
is it hard crossing Silkies with other breeds? Or am i just terrible unlucky?
thanks for any advice:D

The older the birds, the less fertile they become....just like in us humans. Get younger birds for a more successful hatch rate.

How many days were the eggs incubated before you candled them?

I can usually tell by day 5 if they will hatch, but only if the eggs are white. I have never been any good at candling brown eggs.

10 days old, i wanted to make sure