When a claim is placed in a submission status (Bill Insurance, Bill Secondary Insurance, Auto Accident Claim, Worker's Compensation, Durable Medical Equipment), a check will be made before submission to ensure that an EDI submission request has been completed (if required by the payer).
If the payer-requested EDI enrollment is not completed, the claim will be updated with a status message of "Missing Information: Payer Enrollment Not Completed."
If the enrollment request has not been initiated, you can do so by going to Billing > Enrollment. You can also check this screen for status if you have already submitted a request.