I'm loading a usercontrol that has your example

https://examples2.ext.net/#/GridPane.../Form_Details/

If I try to perform the following function

 public void LoadUserControl(string ucName, Ext.Net.Panel ucPanel, bool update = false)
        {
            if (update && ucName != null)
            {
                ucPanel.ContentControls.Clear();
            }

            System.Web.UI.UserControl userControl = (UserControl)this.LoadControl(string.Format("{0}.ascx", ucName));
            userControl.ID = "UC" + new Random();
            ucPanel.ContentControls.Add(userControl);

            if (update)
            {
                ucPanel.UpdateContent();
            }
        }
it loads the usercontrol with the object fine, however a refresh or reload ends in an error due the to paging toolbar (cannot find items)

Unhandled exception at line 1086, column 18 in http://localhost:12011/extnet/extnet...xt.axd?v=40838

0x800a138f - JavaScript runtime error: Unable to get property 'items' of undefined or null reference

Removing the toolbar from the gridpanel solves the error, can you confirm this is a bug or not and recommend a recourse to correct it? Thanks!