How to: Show Add-in User Interface Errors
By default, if an add-in attempts to manipulate the Microsoft Office user interface (UI) and fails, no error message is displayed. However, you can configure Microsoft Office applications to display messages for errors that relate to the UI.
You can use these messages to help determine why a custom Ribbon does not appear, or why a Ribbon appears but no controls appear.
To show add-in user interface errors for Microsoft Office Word, Excel, and PowerPoint applications
Start Microsoft Office Word, Excel, or PowerPoint.
Click the Microsoft Office Button.
Click Word Options, Excel Options, or PowerPoint Options.
In the categories pane, click Advanced.
In the General section of the details pane, select Show add-in user interface errors, and then click OK.
To show add-in user interface errors for Microsoft Office Outlook
Start Microsoft Office Outlook 2007.
On the Tools menu, click Options.
In the Options dialog box, click the Other tab, and then click Advanced Options.
In the Advanced Options dialog box, select Show add-in user interface errors, and then click OK.
Click OK to close the Options dialog box.