Country selection no longer working

I recently upgraded from 1.3 to 1.3.6. Most of it went well. I do have one issue. My customers get an error if they try to select United States as the country. The default is the US, so it isn't allowing them to select this. How do I fix this?

My site is https://www.long2consulting.com/catalog

Thanks in advance!
Linda

I got this to work. It was fixed in 1.3.6 but I had old files in my template override folder. I found that when I replaced
tpl_modules_address_book_details.php
tpl_modules_checkout_address_book.php
tpl_modules_create_account.php

That is now works. I found this in another thread.

My bad.
Linda

Check to see if your overrides for any of the login and create account or anything with address are out of date ...

It looks as if they are ...

As a test, you can also try switching to Classic to see if this fixes the problem, providing you habe not altered the original core files or /classic files to see if this is specifically template related ...

EDIT: Oh ... I see you already discovered the same thing :)