Go back through the steps. You have to answer each of the questions leading up to the entry of the taxes and property id. Otherwise, it could be the information sheet holding you up or some other form, see available forms here.
I am getting the same message for my Michigan return and that is because Michigan won't accept the return until after January 31. Maybe the same in IL?
Now that the IRS is accepting returns, the state tax returns should be following along soon.
The Illinois Department of Revenue (IDOR) announced that it will begin accepting and processing 2023 tax returns on January 29, the same date the Internal Revenue Service begins accepting federal income tax returns.
You can check form availability here: Tax form availability tool,
I am having this same issue with my Illinois return. I've confirmed all the answers, the amount paid, etc. and everything is correct. However, the state review step continues to require review of the property tax credit.
I'm not sure if this matters, but I just kept clicking continue, even though the review message was still active. When the "Complete Check" was run, there was no review message and it appears as though I can move forward and file. I intend to preview the state form to ensure my property tax information is complete.