Turns out transcript is missing a page, and I already submitted the application. School says no changes can be made. What now?

[Happens_2u]

It's through EngineeringCAS. I used one of the "optional documents" slots to add my transcript, and it let me, but will anyone actually read it?

Text of email I received back:

"You may not update any documentation on your application, once you hit the submit button, and pay the fee. The only updates that can be made at this time is the letters of recommendation you have already requested can be submitted, and your official test scores sent to EngineeringCAS can still be added to your application. "

What do I do from here?