Neb. Rev. Stat. § 77-1844: Real property taxes; treasurer's tax deed; condition required to question title.

No person shall be permitted to question the title acquired by a treasurer's deed without first showing that he, or the person under whom he claims title, had title to the property at the time of the sale, or that the title was obtained from the United States or this state after the sale, and that all taxes due upon the property had been paid by such person or the persons under whom he claims title as aforesaid.