I don't know the details of your return, but it is possible that your property tax deduction is being limited by the new $10,000 cap now imposed on total itemized deductions for taxes. This would include all deductions for taxes, including state and local tax withholding, state and local personal property taxes, etc.

You would enter your property taxes under the Personal section of your return under Deductions & Credits / Your Home / Property Taxes.  You'll enter your property taxes in the line "Property tax on your main home".  

If my answer did not completely answer your question, can you explain your issue in greater detail?  I'd like to be able to help you further.

This is the first deduction I am entering. Main home and additional have $0 entered and I can not change it.  Foreign real estate is blank and I could enter there.

Have you tried switching to the Forms view (Ctrl+2), opening Schedule A, then double-clicking on the entry field for line 5 b? If you do that, you'll be taken to the Tax and Interest Deduction Worksheet where you can manually enter it there.