765 ILCS 45/18
No tax deed or certificate of tax sale based on any proceedings, the record of which shall appear to have been destroyed, as aforesaid, shall be received in any of the courts of this state as prima facie evidence of the regularity of such proceedings, but the burden of proof shall be upon the person claiming under such deed or certificate to show the regularity and legality of all such proceedings; in order to sustain the validity of any tax deed or sale for any tax or taxes, assessment or assessments, in any county to which the provisions of this act are applicable, in any suit or proceeding whatsoever, it shall be necessary for the party relying upon any such deed or sale to show, affirmatively, that each and all the provisions of law, in respect to assessment, levy, sale and deed of the lands affected or to be affected by any such deed or sale as aforesaid, have been in all respects complied with--and no presumption shall be indulged in favor of any such tax deed or sale: and it shall not be sufficient to show a collector's report, notice, judgment, order of sale, sale notice, notice of sale, tax affidavit, and deed, anything in this law or in any other law of this state to the contrary notwithstanding.
765 ILCS 45/18