In every case in which, under the provisions of any ordinance of this county in effect at the date Ordinance No. 420 took effect, a license or permit is required for the establishing, maintaining, or conducting of any business use and the business use exists as a nonconforming use under this chapter, then the license or permit shall not be authorized, issued, renewed, re-issued or extended for the business use unless and until a conditional use permit has been secured for the continued maintenance or conducting of the business use. (Prior gen. code § 8-62.9)