To reproduce: - Add a grid to a split panel. - Edit a cell and resize the panel without ending the edit. - Click back in the same cell. Workaround: private void RadGridView1_CellEditorInitialized(object sender, GridViewCellEventArgs e) { BaseGridEditor editor = e.ActiveEditor as BaseGridEditor; var element = editor.EditorElement as RadTextBoxEditorElement; if (element != null) { element.TextBoxItem.HostedControl.LostFocus -= HostedControl_LostFocus; element.TextBoxItem.HostedControl.LostFocus += HostedControl_LostFocus; } } private void HostedControl_LostFocus(object sender, EventArgs e) { this.RadGridView1.EndEdit(); }