Thanks a lot,Paul.

I upgraded my binaries,but the same error occurred,
And MapWindow GIS has no problem.

My souce code is very simple.

Public Class Form1

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

    LoadData()

End Sub

Private Sub LoadData()

    Dim sfWorld As New MapWinGIS.Shapefile

    OpenFileDialog1.Filter = "Shape Files (.shp)|*.shp|All Files (*.*)|*.*"
    If OpenFileDialog1.ShowDialog = DialogResult.OK Then
        sfWorld.Open(OpenFileDialog1.FileName)
        AxMap1.AddLayer(sfWorld, True)
    End If

End Sub

End Class

That's all.

And the Shape file is "world_adm0.shp".It's not special.

If I don't use AxMap,I can debug in IDE and no error.
For example,the code which convert shape file to KML file is OK.