1099-Misc Box 3 Schedule C: unable to fill anything and app refusing to e-file without

We would love to help you but need more information. Please clarify your question.  Are you saying that you have a 1099-MISC without any numbers in box 3?

Yes:

Are there numbers in box 1 or box 2 of your 1099-MISC?  Please clarify.

All other "Box"es are empty.

It's still not quite clear what you have or need assistance with.

1. If you are trying to remove a 1099-MISC because you don't have one this year follow the steps below to delete a form from your file.
2. If you have self employment and the income is reported on a 1099-MISC instead of the appropriate Form 1099-NEC you can add the income on Schedule C for self employment following the steps below without any separate entry for the 1099.  Be sure to delete this form if you did try to enter it.
   1. Open or continue your return.
   2. Search for schedule c > Press enter  > click the Jump to link in the search results.
   3. Answer Yes to Did you have any self-employment income or expenses?  (see the image below)

You'll need to delete this form 1099-MISC. 

• If you're using TurboTax Online software and need to delete a form, click here.
• If you're using TurboTax CD\Download software and need to delete a form, click here. 

@grosserer 

I think going through the self-employed forms somehow fixed the box, thx!