I struggled with this : rejected 3 times! Used help twice. I finally resolved the issue:
Revisit your state return, and go through the prompts until you come to where you electronically signed. Under that number is a tiny box. Uncheck it. Like magic you will see another area appear where you can sign using your IL pin number OR a valid driver's license/ state id. After that you can submit like normal.
I can say mine was then accepted.
