private void LoadConvertionTree() { Convertion_TreeViewItem.Items.Clear(); convertionTreeListItem = ValidationData.LoadConvertionTreeListItem(sLoadFolder); if (convertionTreeListItem != null) { AddConvertionListItem(convertionTreeListItem); } else { string sMsg = ValidatorSDK.ValidationData.sFileConvertionTreeListItem + @" doesn't exist"; MessageBox.Show(sMsg, "File load error", MessageBoxButton.OK); } }