You know all the judge is gonna be worried about is that he can show him a reciept showing he paid thats gonna be the judges mission so if someone can show that he is going to make future payments he should be fine

Its not likely that a judge would jail him for back child support in this case since putting him in jail erases any ability for him to do anything about paying it back. The man is making an attempt and following what the court asked him to do.

His ex may want a change of the agreement but unless your husband's income situation has changed dramatically or the needs of the kids are extremely different, a judge may wonder what has changed. Yes, your husband should have tried to stay on track with the child support but he is trying to right that wrong and a court will take that into consideration.

If he only owes back child support and the children are now adults, the court isn't going to modify the order to increase child support. Now, if your situation has changed, you are unable to pay, and you can show that the children do not need the support due to a disability, you may be able to get the court to terminate the child support order. If you owe her a lot of money, the court may choose to terminate the child support agreement and issue a judgment to her in the amount that you owed her. That way it is out of child support court and she will have to take other action to collect on the judgment, such as collecting when you sell a piece of property or something of that nature. It wouldn't require you to make anymore monthly payments, but the judgment would be in effect for a number of years (probably 10) and would need to be paid if you ever want to do somthing like buy or sell property, get a large bank loan, apply for mortgage credit, etc.
Good luck. Hope it all works out for you.