Each property to which the county does not have title under the provisions of this article shall be subject to Article VI unless title to these properties which have been acquired under Article VII shall have been ratified, confirmed and validated in the manner provided by law for the validation of titles by the court of common pleas of the county in which each property is located, upon proof of title to the property. Any titles ratified, confirmed and validated pursuant to this section shall not be challenged or invalidated thereafter by reason of any defect whatsoever in the acquisition or retention thereof, notwithstanding any law or act of Assembly to the contrary.