Most likely because some state forms were not yet available when you originally tried to efile. Please answer the 2 questions below, and we can tell you how to proceed.
What state is it?
Has your efiled Federal return been accepted?
All the Ohio forms appear to be available according to this FAQ:
State Forms Availability Table:
https://ttlc.intuit.com/questions/1908857-state-forms-availability-table-for-turbotax-individual-per...
Since your Federal return has already been accepted, and if all the state forms you need are available, you
can then
go back and open up your State return to complete and file it. Carefully review
it before filing since the forms may have updated since you last worked
on it.
NOTE: When you go back to your account to finish and
file your return, you may see a notice to finish and file the state
return. If so, you can follow that path to see if it gets you back to
the state return.
If it doesn't, here's a way to open the state return back up: