Have you tried filling out the 4136, overriding the credit on the 1120S, and attaching a PDF of the 4136, then try to efile? (Might have to turn off error checking).

That's how we had to do it years ago before ProSeries even included the 4136.

Might be worth a try just for kicks. No downside if it doesn't go through other than a few minutes of your time.