As I can activate the class "error" in the location field, when the user does not complete the required fields of the form. ?

Note: By default it always appears with the "valid" class green color.

What is the question?
Required fields can be added or removed in admin panel in theme settings.

Hi,

njsb777 has a point, there's a small bug with the theme here - this field only gets red error class if location is used in settings. If you use country or region it always looks ok, although error message shows up on top. Moreover, if you use country and region, on input you need to click on the suggested link - if you just type it, it wouldn't be recognised as valid input (maybe you can confirm this).

Thanks

@ColdFusion
Reason is that country, region and city is selected via one box. If country, region or city is missing, it is identified on different level on different inputs...