How to fix error IL1040-8100-1 ?

[JohnB5677]

You can check several areas that can cause error IL1040-8100-1 to occur.

• Check the prior-year Illinois Adjusted Gross Income (AGI),
• Double-check the 8-digit IL-PIN,
• Be sure the posting of the Driver’s License/State ID details is correct

This will have to match the Illinois Department of Revenue records. 

• Correct these inputs in the state section, 
• If issues persist, print and mail your return. 

[Mike9241]

there is no requirement to enter your DL, just answer you don't have one nor a state ID. The Illinois PIN is the same as used last year, unlike the IRS 5-digit PIN, which you can change every year.

if you filed late, try using $0 for AGI. If you amended, I think Illinois wants the AGI from the amended return, whereas the IRS wants the AGI from the original return if filed timely