Did you file a SCH C with your 2015 return? If yes, then did you report the sale, closure or other disposition of your business on the 2015 return? If you did not, then the IRS is expecting a SCH C from you this year. If they are expecting one and don't get it, then it will come back to bite you 24-36 months down the road.
Otherwise, provided you have NOT paid any turbotax fees yet, with your return open click My Account at the top right and select the clear and start over option. A few screens later you can select what flavor you desire to start your 2016 tax return with.
If you have already paid your online fees, then you can't clear and start over.
