Problem in drop down list binding.

Thanks for revert. I am sharing my running code, which is running from last 4 year. Now suddenly from couple of days back I am facing this binding issue in only for one drop down list and rest drop down are binding fine in other page.

 

Try
If Not IsPostBack Then
FillService()
End If
Catch ex As Exception
//Exception code
End Try

 

Private Sub FillService()
Dim objService As Service
Try
ddlService.DataSource = List(rblServiceType.SelectedValue)
ddlService.DataTextField = "servicename"
ddlService.DataValueField = "serviceid"
ddlService.DataBind()
ddlService.Items.Insert(0, (New ListItem("--Select--", "0")))
Catch ex As Exception
Throw ex
End Try
End Sub