I have 3 forms 1099-NEC. I have carefully filled in all the information, but it's telling me that it's missing info and that the forms will be deleted.

[statmanlee]

I have checked and double checked, deleted them and filled them all in again, and still says that there is missing info on all 3, when there isn't.

[RayW7]

You can go to the forms mode and review each of the 1099-NEC forms.  Look for a 'Red !' or a highlighted area inside the form for fields that may need correction.  

To switch to Forms Mode, open your return and click the Forms icon in the upper-right corner of your screen (or choose Forms from the View menu at top).

The 1040 Worksheet will display and all the forms in your return will be listed on the left side. Simply select a form to open it.

To switch back to the interview, click the Step-by-Step icon in the upper right corner, or choose it from the View menu.

-for additional information on 1099-NEC follow this link-

How to File Taxes with IRS Form 1099-NEC - TurboTax Tax ...

[VolvoGirl]

The Online version does not have the Forms Mode.  So the answer above won't work if you are using the Online version.   I would forget about entering the 1099NEC. Just enter the total as Other self employment income or as Cash or General income. You don't need to enter each 1099NEC or 1099K. You can enter all your income as Cash. Only the total goes to schedule C.

How to enter income from Self Employment
https://ttlc.intuit.com/community/self-employed/help/how-do-i-report-income-from-self-employment/00/...