What will happen if something was left out of the divorce decree that was in the separation agreement?

You need to ask the Court to amend the divorce decree.

It depends on what? there is not enough information to say if it is important you can always try to amend the divorce judgment.

Usually the Judgment will have language adopting/ratifying and incorporating the MSA into the Final.

In Utah (and I'm speaking generally here), if something was included in a settlement agreement or some other document that the parties agreed should be included in their final decree of divorce, and there's little to no question on that point, then you and your ex spouse can simply stipulate to amend the decree of divorce to include the provision that was inadvertently omitted originally. If an agreed-upon provision that was left out happens to benefit you or your ex spouse and you or your ex-spouse wants to keep it out, that's immoral, but the law may prevent that provision from being included in the divorce decree was not included at the beginning. If you believe you can make a clear showing that the omission of the provision was inadvertent and clearly should have been included in the decree but for a mutual mistake or a clerical error, you can file a motion with the court to amend the decree to conform with the parties? agreement. Simply filing such a motion does not guarantee that you will succeed, but without filing such a motion you cannot succeed. This is a situation where you owe it to yourself to meet with a skilled divorce lawyer to learn your options and your odds for success. This is the kind of situation also where paying an attorney for a consultation is a good investment. Certain free consultations may be a financial boon, but when it comes to consultations like this, when the consultation is free you usually get what you pay for pay for.

If the divorce decree references the agreement, then it may be there by implication. If not, you can always ask the court to amend the decree to include the missing information.

You should ASAP file a Motion with the Court, requesting the Judgment of Divorce to be modified by an Order, to specifically include whatever was left out from the separation agreement. Time is of the essence in your situation, so please don't delay.