What is wrong with this Widget Extension?

Have you enabled the extension on your site?  You also need to match the capitalization you defined in your extension.  It is defined as Ibby_v1_LocationData, but you are attempting to use it as ibby_v1_LocationData.

That worked, thanks. Also, can I return an array of objects? will that work?

I don't think there would be any reason an Array could not be returned.

I have modified the Widget Extension to return an array of objects, but they are not getting output as I want. Here's the code:

namespace LocationData
{
    public class Location
    {

        public Array GetAllCountries()
        {
            SqlDataAccess sd = new SqlDataAccess();
            SqlCommand sc = sd.GetCommand("EXEC ibby_GetAllCountries");
            DataTable dt = sd.Execute(sc);
            Item ct = new Item();
            List<Item> li = new List<Item>();
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                ct = new Item();
                ct.iso2 = dt.Rows[i]["iso2"].ToString();
                ct.country = dt.Rows[i]["country"].ToString();
                li.Add(ct);
            }
            return li.ToArray(); //dt.AsEnumerable().Select(r => r.Field<string>("country")).ToArray();
        }

    }

    public class LocationWidgetExtension : IScriptedContentFragmentExtension
    {
        #region IScriptedContentFragmentExtension Members

        public string ExtensionName
        {
            get { return "Ibby_v1_LocationData"; }
        }

        public object Extension
        {
            get { return new Location(); }
        }

        #endregion

        #region IPlugin Members

        public string Name
        {
            get { return "GetLocationData"; }
        }

        public string Description
        {
            get { return "Get Location Data"; }
        }

        public void Initialize()
        {
        }

        #endregion
    }

    public class Item
    {
        public string iso2;
        public string country;
    }

}

And here's the Velocity

#set ($countries = $Ibby_v1_LocationData.GetAllCountries())
#foreach($item in $countries)
    <span>$item.iso2</span>|<span>$item.country</span><br/>
#end

And this is what is being output:

$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country
$item.iso2|$item.country

I would recommend returning a List<Item> rather than an Array.  Since the array is not typed, velocity does not know what the Objects inside it are.

I have changed it to return a List<Item>, but it is still not working.

Is the output the same?

Have you tried using $core_v2_utility.Describe, that might help identify if your object is built as you expected it.

#set ($countries = $Ibby_v1_LocationData.GetAllCountries())
$core_v2_utility.Describe($countries)
#foreach($item in $countries)
    $core_v2_utility.Describe($item)<br/>
#end

Yes, the output is the same. Here's the output when using $core_v2_utility.Describe (note that I have changed the class name to CountryItem)

[List-of-CountryItem]

• [0] [CountryItem]
• [1] [CountryItem]
• [2] [CountryItem]
• [3] [CountryItem]
• [4] [CountryItem]
• [5] [CountryItem]
• [CountryItem]
• [7] [CountryItem]
• [CountryItem]
• [9] [CountryItem]
• [10] [CountryItem]
• [11] [CountryItem]
• [12] [CountryItem]
• [13] [CountryItem]
• [14] [CountryItem]
• [15] [CountryItem]
• [16] [CountryItem]
• [17] [CountryItem]
• [18] [CountryItem]
• [19] [CountryItem]
• [20] [CountryItem]

Are the properties of CountryItem being populated in C# code?  Correct capitalization on the property names when you request them?  $item.Iso vs $item.iso?

I believe so. Here's the C# code:

namespace LocationData
{
    public class Location
    {

        public List<CountryItem> GetAllCountries()
        {
            SqlDataAccess sd = new SqlDataAccess();
            SqlCommand sc = sd.GetCommand("EXEC ibby_GetAllCountries");
            DataTable dt = sd.Execute(sc);
            CountryItem ct;
            List<CountryItem> li = new List<CountryItem>();
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                ct = new CountryItem();
                ct.iso2 = dt.Rows[i]["iso2"].ToString();
                ct.country = dt.Rows[i]["country"].ToString();
                li.Add(ct);
            }
            return li; //dt.AsEnumerable().Select(r => r.Field<string>("country")).ToArray();
        }

        public List<RegionItem> GetRegionsInCountry(string iso2)
        {
            SqlDataAccess sd = new SqlDataAccess();
            SqlCommand sc = sd.GetCommand("EXEC ibby_GetRegionsInCountry " + iso2);
            DataTable dt = sd.Execute(sc);
            RegionItem ct;
            List<RegionItem> li = new List<RegionItem>();
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                ct = new RegionItem();
                ct.admin_code = dt.Rows[i]["admin_code"].ToString();
                ct.admin_name = dt.Rows[i]["admin_name"].ToString();
                li.Add(ct);
            }
            return li; //dt.AsEnumerable().Select(r => r.Field<string>("country")).ToArray();
        }



    }

    public class LocationWidgetExtension : IScriptedContentFragmentExtension
    {
        #region IScriptedContentFragmentExtension Members

        public string ExtensionName
        {
            get { return "Ibby_v1_LocationData"; }
        }

        public object Extension
        {
            get { return new Location(); }
        }

        #endregion

        #region IPlugin Members

        public string Name
        {
            get { return "GetLocationData"; }
        }

        public string Description
        {
            get { return "Get Location Data"; }
        }

        public void Initialize()
        {
        }

        #endregion
    }

    public class CountryItem
    {
        public string iso2;
        public string country;
    }

    public class RegionItem
    {
        public string admin_code;
        public string admin_name;
    }


}