It looks like the reason you are seeing this error is because you have entered "0 days" for subsistence allowance. Removing the 0 would solve the problem.
To remove the 0:
1. Go back to your return and click on State Taxes. Click on Edit for South Carolina.
2. Once you get the screen stating that your South Carolina are ready to be checked. Click Edit beside the Income section.
3. This opens a page titled “Here’s the income that South Carolina handles differently".
4. Scroll down that page to Public Service > Subsistence Allowance.
5. Click Start (or Revisit), enter the number of days, then click Continue
6. On the page "Emergency Personnel Subsistence Allowance", if there is a "0" for number of days, remove the "0" and click Continue.
This should fix your error that's stopping you from efiling.
