Why couldn't I complete the e-filing of my State of Oregon return? Turbotax would not let me submit my billing information.

Did you already e-file a federal return?

Yes, within the last hour. I was trying to submit them both at the same time.

That is the problem.  Since you filed the federal separately, you will need to wait until the Federal has been accepted.  Once it is accepted, TurboTax will accept your payment and allow you to e-file your Oregon return.  You can't file a state before the federal, so TurboTax has to be sure the federal is accepted first.  

The instructions were not clear on that in the software, or else I missed it...Also, I highly prefer getting to talk to a live person rather than this method. But...thanks for answering in a clear, timely manner.