Dictionary error with Facebook SDK

I am trying to get the user's locale but I am having trouble doing so. My App has been approved by facebook to use the user_location permission.

In my script I request the permission with: permissions.Add("user_location");

then

FB.API("/me?fields=location", HttpMethod.GET, DisplayLocation);

void DisplayLocation(IResult result)
{
if (result.ResultDictionary.ContainsKey("locale"))
{
FacebookLocation = result.ResultDictionary["locale"];...

Dictionary error with Facebook SDK