Deductions & credits

Sorry, I don't understand this answer. The link to delete a form from a download first asks me to sign in. Why? I am using a download. Secondly it says deleting a form is not a good idea. Thirdly, on a Mac, I see no way to do so. There must be a more appropriate answer for this, especially for Mac users. 

 

This error has been there since the release. In error check it says I need to input advance child credit payments on schedule 8812 in section letter 6419 smart worksheet. I have no child I have no payment. If I put a zero in the box and run error check again it says I can't enter anything in that box!

 

Help!