Success:
We had the same problem We knew for sure it was right, but even ordered the info from irs.gov to confirm. Entered it again, no success.
Out of desperation before printing the whole thing, we tried $0 and that worked.
To the many who have the same problem: give that a try: $0.
My guess, the software branches to "was zero entered" before rejecting. Kind of like a backdoor or cheatcode.
