Under the Business Info tab select the About Your Business sub-tab. Then scroll down and see what you have tor "Date business Began"
There's three times in that section.
Date You Incorporated - Must be on or after the date business started.
Date of S Election - Must be on or before date business Incorporated, and on or after date business started.
Date Business Started - Must be on or before both dates above.
All three dates above can be the same.
In your case, if your business started on or before 12/31/2016, then expenses incurred on 12/31/2016 are not startup expenses. Your startup expenses must be incurred *before* the "Date Business Started" date.
If not clear, then give me a screenshot of the "About your Business" screen, making sure to blank out any personally identifiable information, and making sure you blank out the business name.
