Calling IEditor::StartEditing after IEditor::StopEditing eliminated the problem:If MsgBox("save your edits?", MsgBoxStyle.YesNo, "Save Changes") = MsgBoxResult.Yes Then m_pEditor.StopEditing(True) For LayerCount = 0 To pMap.LayerCount - 1 If TypeOf pMap.Layer(LayerCount) Is IFeatureLayer Then pFeatureLayer = pMap.Layer(LayerCount) pDataset = pFeatureLayer.FeatureClass m_pEditor.StartEditing(pDataset.Workspace) Exit For End If Next LayerCount