This happens when you try to enter your property taxes in the same section with mortgage interest and you don't have a mortgage.  To solve this problem:

Delete your first property tax entry

1. Click on Federal > Deductions & Credits 
2. In the Your Home section, start by clicking on the Start/Revisit box next to Mortgage Interest, Refinancing, and Insurance (Form 1098).
3. If you see the screen, Review your 1098 info, click the delete icon (the trashcan) next to your entry.
4. If you don't see the screen, continue through the interview until you reach Let's get the details from your [lender name] 1098.  Remove the number from the Property (real estate) taxes box.
5. Click the Back button until you are back on the Deductions & Credits screen.

Reenter the Property Tax

Since you do not have a mortgage, please follow these steps to enter your property tax:

1. In the Your Home section, start by clicking on the Start/Revisit box next to Property Taxes. 
2. Enter your taxes on the next screen, Enter the Property Taxes You Paid.