This is an issue on the IRS side, it is a "known issue" the IRS has logged here: <a rel="nofollow" target="_blank" href="
https://webcache.googleusercontent.com/search?q=cache:ZIurjNAOqcQJ:https://www.irs.gov/pub/irs-schem...>
I called TurboTax and the support person was able to see more explicit detail of the rejection reason. If the person is 1) Married Filing Separately and 2) has an amount in box 10 of their W-2 (dependent care FSA) then the IRS system will reject the e-file due to this bug on their side. The support person with TurboTax told me the IRS says it will be resolved March 17. I will likely be mailing the return because I think this issue on the IRS side is specific to their program that auto-processes e-filed returns.
