Why ribbon XML does not work in Excel 2007?

Question

I installed 4 VSTO Excel add-ins on an Excel 2007 PC today. The two that use a visual designer ribbon worked fine. But the 2 that use a Ribbon (XML) did not. The add-in starts ok. But the ribbon does not show. Why would that be?
I wrote two more add-ins to demonstrate the problem. One puts an OK button on the ribbon using the visual designer. That add-in installs on the excel  2007 PC and works as it should. But the 2nd, an add-in that uses Ribbon (XML) to put a button on the
ribbon, does not work.  The add-in does not display on the ribbon.
Here is the code of the Ribbon (XML) add-in project.  How to get a ribbon (XML) ribbon to display in excel 2007?
thanks,
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using Excel = Microsoft.Office.Interop.Excel;
using Office = Microsoft.Office.Core;
using Microsoft.Office.Tools.Excel;
namespace ExcelAddIn4
public partial class ThisAddIn
private void ThisAddIn_Startup(object sender, System.EventArgs e)
private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
protected override Office.IRibbonExtensibility CreateRibbonExtensibilityObject()
return new Ribbon1();
#region VSTO generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InternalStartup()
this.Startup += new System.EventHandler(ThisAddIn_Startup);
this.Shutdown += new System.EventHandler(ThisAddIn_Shutdown);
#endregion
<?xml version="1.0" encoding="UTF-8"?>
<customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui" onLoad="Ribbon_Load">
<ribbon>
<tabs>
<tab idMso="TabAddIns">
<group id="ContentGroup" label="Content">
<button id="Button1" label="ok" screentip="Text"
onAction="Button_OnAction" supertip="Inserts text at the cursor location"/>
</group>
</tab>
</tabs>
</ribbon>
</customUI>
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows.Forms;
using Office = Microsoft.Office.Core;
// TODO: Follow these steps to enable the Ribbon (XML) item:
// 1: Copy the following code block into the ThisAddin, ThisWorkbook, or ThisDocument class.
// protected override Microsoft.Office.Core.IRibbonExtensibility CreateRibbonExtensibilityObject()
// return new Ribbon1();
// 2. Create callback methods in the "Ribbon Callbacks" region of this class to handle user
// actions, such as clicking a button. Note: if you have exported this Ribbon from the Ribbon designer,
// move your code from the event handlers to the callback methods and modify the code to work with the
// Ribbon extensibility (RibbonX) programming model.
// 3. Assign attributes to the control tags in the Ribbon XML file to identify the appropriate callback methods in your code.
// For more information, see the Ribbon XML documentation in the Visual Studio Tools for Office Help.
namespace ExcelAddIn4
[ComVisible(true)]
public class Ribbon1 : Office.IRibbonExtensibility
private Office.IRibbonUI ribbon;
public Ribbon1()
public void Button_OnAction(Office.IRibbonControl control)
MessageBox.Show("Button_OnAction");
#region IRibbonExtensibility Members
public string GetCustomUI(string ribbonID)
return GetResourceText("ExcelAddIn4.Ribbon1.xml");
#endregion
#region Ribbon Callbacks
//Create callback methods here. For more information about adding callback methods, visit http://go.microsoft.com/fwlink/?LinkID=271226
public void Ribbon_Load(Office.IRibbonUI ribbonUI)
this.ribbon = ribbonUI;
#endregion
#region Helpers
private static string GetResourceText(string resourceName)
Assembly asm = Assembly.GetExecutingAssembly();
string[] resourceNames = asm.GetManifestResourceNames();
for (int i = 0; i < resourceNames.Length; ++i)
if (string.Compare(resourceName, resourceNames[i], StringComparison.OrdinalIgnoreCase) == 0)
using (StreamReader resourceReader = new StreamReader(asm.GetManifestResourceStream(resourceNames[i])))
if (resourceReader != null)
return resourceReader.ReadToEnd();
return null;
#endregion

Answer 1

Hello Steve,
Most probably you have got an error in the ribbon XML markup. See
How to: Show Add-in User Interface Errors for more information.
I have noticed the following xml namespace:
<customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui" onLoad="Ribbon_Load">
Use the following one instead:
<customUI xmlns="http://schemas.microsoft.com/office/2006/01/customui"
Also make sure that specified idMso values exist in Office 2007.
You can read more about the Fluent UI (aka Ribbon UI) in the following series of articles in MSDN:
1.
Customizing the 2007 Office Fluent Ribbon for Developers (Part 1 of 3)
2.
Customizing the 2007 Office Fluent Ribbon for Developers (Part 2 of 3)
3.
Customizing the 2007 Office Fluent Ribbon for Developers (Part 3 of 3)