New Post: Creating a Shape File

I am not sure why it wont save it in the first place. But when I try to save a Shape File, it errors, I get the following error. I cant figure out what I am missing.

Here is the Code:
Dim returnval As DotSpatial.Data.FeatureSet = New FeatureSet(ShapeType)

        returnval.Projection = DotSpatial.Projections.KnownCoordinateSystems.Geographic.World.WGS1984

returnval.DataTable.Columns.Add(New DataColumn("MyTest", GetType(System.String)))
returnval.SaveAs(String.Format("{0} ", "C\MyFolder\TestShapeFile.shp"), True)



'he specified file type is not supported. at DotSpatial.Data.DataManager.CreateVector(String fileName, FeatureType featureType, IProgressHandler progHandler) in g:\TeamCity\buildAgent\work\8dcaae3a01f0640d\Trunk\DotSpatial.Data\DataManager.cs:line 166
at DotSpatial.Data.FeatureSet.SaveAs(String fileName, Boolean overwrite) in g:\TeamCity\buildAgent\work\8dcaae3a01f0640d\Trunk\DotSpatial.Data\FeatureSet.cs:line 909 at RevCoreService.RevCoreService.CreateShapeFile(FeatureType ShapeType, ObservableCollection`1 columns, String ShapeFileName) in C:\Visual Studio 13\Projects\RevCoreService\RevCoreService\RevCoreService.vb:line 131



First question is Why does it not save?

Second is : What is with "g:\TeamCity\buildAgent\work\8dcaae3a01f0640d\Trunk\DotSpatial.Data\DataManager.cs:line 166"