This addin caused outlook to start slowly

Question

I am developing an Outlook Addin Project using C#.NET 4.5 But After I deploy, Sometimes outlook disables my addin, and shows this message. "This addin caused outlook to start slowly"" I dont know whats wrong with my addin. This has only a few codes, and ThisAddIn_Startup is empty in this project. Here is the code...

   public partial class ThisAddIn
   {
   private void ThisAddIn_Startup(object sender, System.EventArgs e)
   {

   }

   private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
   {
   }
   protected override Microsoft.Office.Core.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"         önLoad="Ribbon_Load">
   <contextMenus>
   <contextMenu idMso="ContextMenuContactItem">
     <menuSeparator id="mniMailItemMenuSeparator" />
     <button id="customButton"
            label="Call using Software"   insertBeforeQ="Copy"
          imageMso="Call"
           önAction="OnMyButtonClick" />

    </contextMenu>
   <contextMenu idMso="ContextMenuMailItem">
     <menuSeparator id="mailmenusep1" />
     <button id="mailbutton" insertBeforeQ="Copy"
          label="Call using Software"

         imageMso="Call"
           önAction="MailItemCallNumbers"   />

   </contextMenu>
  </contextMenus>

 </customUI>

Answer 1

Starting with Outlook 2013, Microsoft introduced new performance criteria for add-ins. For more information see http://msdn.microsoft.com/en-us/library/office/jj228679.aspx#ol15WhatsNew_AddinDisabling

In your case, Outlook is loading the .Net framework and is considering the cost as part of your add-in. Native COM add-ins tend to load faster than .Net add-ins.

As the article points out (in the section "System Administrator control over add-ins", there is a Group Policy setting that allows you to specify which add-ins are always enabled, always disabled (blocked), or configurable by the user.

Though not recommended, as Outlook does when "Always enable this Add-In" is selected (as described here), you could directly add your add-in to the following registry key.

HKCU\Software\Microsoft\Office\15.0\Outlook\Resiliency\DoNotDisableAddinList

For improving the performance of VTSO based add-in, see Performance Improvements Coming Soon to a Service Pack Near You

For changing when an add-in is loaded, see Delay-loading the CLR in Office Add-ins.

Answer 2

This can happen on an empty project if you build your add-in in debug mode and attach the debugger to it. The added time required to load all the symbols files into the debugger when it get attached might take longer than Outlook is expecting for a "stable" plugin to initialize.

You shouldn't worry about this unless it happens in a release build with no debugger attached. During development, you can simply tell outlook to never disable your plugin.

Answer 3

Try delay loading of your addins. Try setting Load Behaviour to 8 or 9 for On-Demand loading.

Check this for more http://blogs.msdn.com/b/andreww/archive/2008/04/19/delay-loading-the-clr-in-office-add-ins.aspx