After correcting errors on a form, saving, and validating, you can create a new external EDI file with Submit.
Check the Status of the submit on the main My Tasks page or at the bottom of the form under Task Actions |Change Status To.
It should say Submitted. If the submit cannot be completed for some reason, the status of that document will be Failed. Ask your TI administrator to check the Event Log for the reason.
Please see Submitting Overview for details.