Try this to correct the signature:

1. Log on to your account, and select Fix my return. 
2. Select File from the left side menu and proceed to the screen titled, Sign Your Illinois Return.
3. Enter your 2018 AGI from line 1 of your 2018 Form IL-1040 (not your federal AGI from your IRS 1040 form); or
4. 8-digit Illinois PIN, which you might be able look up at the Illinois Department of Revenue's website; or
5. Illinois driver's license number or State ID. 

Note if you don't have at least one of these items, you will not be able to e-file your state return. 

It never had me put in a 8 digit Illinois pin in my return. This has to be if you select a different form to verify yourself other than Drivers License or AGI.

I can't get to the sign my tax page to enter in the IL-PIN. It skips past the page where I enter the IL AGI information. Please help.

Also I paid to efile this tax return. Will I have to pay again?

thanks. 

It took me 5 submissions but got it to submit with NO reference to AGI. I assume that since TurboTax requires a period at the end of the entry that Illinois is rejecting it. I tried without the period, I tried with 00 after the period, I tried to remove the comma—TurboTax kept putting the period and comma in. Illinois kept rejecting both secondary and primary taxpayers but finally got it to work with only driver’s license.