I can not understand either.
Here is what I think is happening...
1.. They are all males.
2. Something is eating the eggs (probably rats).
There is no other reason I can think of that the birds are not laying eggs. It can happen with disease, like Salmonella, where the females reproductive organs are damaged, but this is highly unlikely to have affected all your female birds!
The OP also said the birds are not even making nests or using the nest boxes. That is weird too. Even all males will pair up and make nests and mate.
Something is very wrong. Perhaps the diet? Maybe they are starving or are not getting the correct nutrients they need? Maybe they are sererly infected with parasites which are sapping they strength so they are not coming into breeding condition?
My advise.
Worm them.
Treat them and the coop for external parasites.
If the poops are runny or not normal... treat them for coccidiosis.
Make sure they are getting a proper diet.. pigeon mix, minerals, vitamins and grit. Fresh water every day.
If still no eggs and they are all plump and healthy looking and acting... presume they are all males and sell some and get females!