I'm filing 1120 corp tax. On state side, f500 has an error. Questions and related information. Line C (2) has the previous year's Federal NOL amount in red. Line C(3) is asking the percent of federal NOL used this year, which is zero. Why is it asking me to attach pdf ? The error says "F500FedNOL requires a statement to be attached in PDF format when efiling." FedNOL was only one year not more than one year. 

Please advise.

Thank you.

Bola