Detecting Errors

The Ribbon markup that you return in the IRibbonExtensibility.GetCustomUI call will usually contain callbacks that run when an Inspector is about to be displayed. For each callback in your Ribbon markup, you must add the callback to the add-in class that implements IRibbonExtensibility. These callbacks must be declared as public procedures. If for some reason you omit a callback or use an incorrect callback signature, then your Ribbon customization will fail silently unless you turn on error reporting when you debug your solution.

Note that if the Ribbon markup returned by GetCustomUI does not entirely follow the Ribbon XML schema, none of the Ribbon customization will be applied. This means, if you have a problem with one control that you have added to the Ribbon, customizations to all other controls in that Ribbon will not be displayed.

To turn on error reporting when your Ribbon markup is loaded, you should follow these steps:

1. In an Outlook Explorer window, click the Tools menu, then click Options, and then click Other.
2. Click Advanced Options, then check Show add-in user interface errors in the In all Office applications frame.
3. Click OK to save changes.