If the home ceased to be your
main home prior to 2016, you would have included Form 5405 in your tax return
for the year it was disposed of/sold, etc. and you would have repaid your
balance on that tax return or in some cases, the balance would have been waived. It
should not be showing an outstanding balance is due, and no 5405 is
required. The reject message you are receiving is because the IRS has not
properly updated its records and believes (based on their info) that a 5405 with a payment is due
in 2016.
You can look up your
account at this link: https://www.irs.gov/individuals/first-time-homebuyer-credit-account-look-up
To resolve this, you will need
to paper file your return this year. Attach
a copy of your return for the year the property was sold, to show that you
properly filed in that year. Additionally, you will need to contact the IRS directly
to have them correct their records so you don't encounter this same issue next
year.