“I haven't filed Illinois tax returns for over 40 years. Until now, I have never owed any taxes (often over paying) and have filed my federal tax returns every year.”----> In general if you don't owe IL taxes you don't have to file unless you want to get your over-withheld money back. There will be a time period like 3 years after which you can't get your money. Usually the state returns take information from the Federal and apply to the state, so if you have your Federal returns, you should be alright.
“ I have never had any contact for non filing from the state. I have filed for and received unemployment, and received the required tax forms for these payments. Once I stopped filing, I got scared to start filing, as I seemed to be under the radar. This year, for the first time, I owe money ($94). I would like to pay, but want to know what trouble I may get myself into when I file.”----> Usually the state returns take information from the Federal and apply to the state, so if you have your Federal returns, you should be alright. I guess you need to contact IL DEpt of revenue for more info in detail.