Do I need to file a state return in Illinois for receiving a form K-1-T when I have lived in another state for last 20 years?

I received a K-1 and K-1-T from an (irrevocable) estate trust that was formed in a different state (Illinois) from where I have lived for last 20 years (Texas).  Am I supposed to file a return (or anything) in Illinois?  I have searched around but everything I have found is either ambiguous or not easily understood.  Ideally, please explain it to me like I am 10 years old.