Did something happen to him in the crate? Even something really minor could freak out a dog. Did something change in the room around the crate? Did you move furniture or is a new piece of electronics causing buzzing or something?
Unfortunately, forcing him in the crate is going to make this worse, because he'll have whatever reason he is afraid and then you forcing him on top of that making him afraid.
Unfortunately, forcing him in the crate is going to make this worse, because he'll have whatever reason he is afraid and then you forcing him on top of that making him afraid.