What do I do if I received an individual income tax failure to file notice?

Did you successfully efile the return ?   Log into your account and look ... scroll down ... what does the state filing status say ?   Look to the left ... does it say printed or something else ? 

Whatever is says you must comply with the state's request for an ink signed paper copy ... send it as directed ASAP. 

If you mailed your Ohio state tax return, you needed to include a copy of your Federal 1040 return with the state return.  Contact Ohio state and find out for sure what is wrong.