Where a party petitions for sale in error of a tax certificate based on a mistake by a county employee regarding the property in question, the mistake must affect the tax sale or collection process or have been detrimentally relied on by the petitioner.The 1st District Appellate Court affirmed the decision of Cook County Circuit Judge Maureen O. Hannon.Gan C LLC purchased almost $1.4 million in delinquent tax certificates from a shopping center in Calumet City at the 2015 Cook County tax sale. The purchase certificate was …