So, if the person selling their house has a tax lien on the home then they have to pay those taxes in the closing fee. Got it. But, what happens if the home does not sell before the tax lien sale occurs? Can the tax lien still be up for auction? Wouldn't this stop the home from being sold?

If the back taxes are not paid prior to the auction, the home can be sold.

But if there is a mortgage on the property, almost 99.9 percent of the time, as long as it is a bank or a commercial mortgage company, they come in at the last minute and pay the taxes, and then either force owner to pay or start their own foreclosures.

That is why you seldom see the large nicer homes actually sell at the auctions.