From this screen, can you click on Continue or Done at the bottom of the page?
If TurboTax thinks you have a second entry, type '1099-b' in the Search area and click on 'Jump to 1099-b'.
At the summary page, delete any entry named 'Untitled' or a second entry for 'Computershare' (click EDIT for Computershare to see if there are two entries).
Click this link for more info on How to Enter 1099-B.