Software for 2016 is no longer available nor is it supported. You could get the 2016orms from the state and prepare it by hand to mail in. Make sure you have a copy of your 2016 federal return handy to refer to.
TurboTax does not support tax year 2016.
Go to this Ohio Department of Taxation website for prior year tax forms - https://tax.ohio.gov/wps/portal/gov/tax/individual/get-a-form