If you are using TurboTax Online, use the Delete a Form feature to find and delete the untitled S Corp K-1 form.
Here's how to delete your form in TurboTax Online:
Click here for the full article on deleting a form in TurboTax.
If you are using a Download/CD version of TurboTax, you can find the untitled S Corp K-1 in Forms mode (icon top right in blue bar). Find the form in the left pane, click on it and it will open in the window, and then click Delete Form at the bottom.