Several people who took my survey a while ago mentioned crate training. Here are the two most challenging situations:
 A year-old Rottweiler who used to go in his crate when asked now doesn’t want to. He can’t be lured with dog biscuits, toys, or other treats. It’s necessary because his owners will be showing him and he’ll have to be crated at the shows.
 A female Jack Russell Terrier “goes ballistic” when put in the crate. She barks and yaps endlessly, and has even gone to the bathroom on herself in the crate, in her stress. The owner has given up on the crate, at least for now.
Hmm… for whatever reasons the two dogs have, each has decided that the crate is bad news. If you can figure out why they came to that conclusion, you’ll be a big step further towards solving the problem. Was there any particular time that they were stressed by being in it?
There’s a long and detailed page about crate training on this site, and reading through my suggestions for how to crate train might provide food for thought about how this dilemma could have arisen and/or what you might do next.
With the JRT, you could use one or more of the alternatives to crate training which I describe on that page, such as an ex pen or confined area, but with the Rottie, you will need to get him to accept the crate willingly. It may be that if you create an alternative space at home temporarily, it will give all of you the time to regroup. Then you could take baby steps with clicker training. Click and treat (when he’s hungry or interested in treats) if he walks anywhere near the crate. Then click if he walks closer to it. Then closer still. Then next to it… then toss a treat just barely in the crate and click if he will take it. And so on. Bit by tiny bit. You could do quite a few very short sessions a day.
Here is a one-minute video with a clever twist on crate training that I put here on this site, made by Dr. Ian Dunbar, one of my favorite dog trainers.
If he were my dog, I would also try to communicate with him telepathically, to find out what the problem is. My husband once produced a program called Telepathic Communication with Animals featuring an outstanding animal communicator named Penelope Smith. (Link goes to description of the program on another site of ours.) The process of making that program made both of us more able to tune in to our own animals. We just sit quietly, preferably with the pet, and close our eyes. We ask a question, inwardly or out loud. We sit in silence for a few minutes and then Kelly and I compare notes. Usually we get similar insights.
By the way, many trainers would say of both these dogs that they are being too dominant and that you need to take on the role of pack leader. I don’t think that way, though I used to, but I don’t find it leads to solutions as effective as you can get with a more positive approach.
That said, it does often happen that as kids grow up, they say no to things that they did willingly earlier — no doubt you are familiar with this with humans! So there could be some “teenage” aspects to the behavior.