Why does it ask me to fix my federal return, doesn't allow me to and the only other option is to file be mail?

You should try deleting that Form 1099-MISC and enter it manually as follows:

Form 1099-MISC is used to report miscellaneous income for individuals and companies who have been paid $600 or more in non-employee service payments during a calendar year.

To enter a Form 1099-MISC into TurboTax you can:

1. Click on the "Search"  icon
2. Enter "1099-MISC" in the search box  
3. Select "Jump to form 1099-misc"
4. It will take you to a screen that says, "Did you get a 1099-MISC?
5. Select "Yes"
6. Enter your Form 1099-MISC information
7. Answer all follow-up screens

If this is one-time payment, non-employee compensation and you are not self-employed make sure when you are entering your Form 1099-MISC to answer the following questions:

1. Did the  (job name) involve work that was (Your name) main job? Answer No
2. Did the (job name) involve an intent to earn money? Answer No

This way this one-time payment will not be entered as self-employment income on a Schedule C.

Your screen will look something like this:

Click here to find information on editing and deleting Form 1099-MISC.

Click here for more information on Form 1099-MISC

Click here for information on entering Form 1099-MISC

Click here for Publication 525 (2024), Taxable and Nontaxable Income