Symfony was looking for me to have a __toString() function in my model so it could create the drop down menu. So for instance, let's say you have tables like countries and states in your schema.xml. Country_id in the states table is a foreign key to the Countries table like so:
When you do:
symfony propel-init-admin backend states States
Symfony is going to create the edit and create actions of the States screens with a drop-down menu of countries that the state is a part of. The value of the country drop down is the country_id. the value needs to be set in a __toString() function in your Country propel model. The easiest thing is to just return a simple string name (if that's in your db model):
That should solve the problem. It's odd that this comes up. And I couldn't find anything on it when googling.