Ribbon/VBA errors - where to see them?

[jjasmith4]

I have a ribbon with a button and a label: the button opens up a data-entry form, and the label is supposed to show the environment. As I'm designing the ribbon XML everything's find until I add the attribute getLabel="modRibbon.GetEnvironment" to the <labelControl> element. Here are the ribbon XML and the whole VBA module named modRibbon.

When I leave out getLabel="modRibbon.GetEnvironment", all is well: the ribbon displays, the button works, and the label shows "Env". When I put it back in, the ribbon doesn't even display, and there's absolutely no clue anywhere as to what could possible be wrong, which is nothing whatsoever! I have followed all documentation scrupulously, and I have spent hours boiling it down to this one attribute, which, for no reason at all is the difference between the ribbon displaying and the ribbon not displaying.

What in hell could possibly possibly be wrong here? And where can I see any error messages?

<customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui" onLoad="modRibbon.RibbonLoaded">
    <ribbon startFromScratch="false">
        <tabs>
            <tab id="customTab" label="Deals">
                <group id="customGroup" label="Maintenance">
                    <button id="customButton" label="Open" imageMso="CreateReportFromWizard" size="large" onAction="modRibbon.Start" />
                    <labelControl id="customLabel" label="Env" getLabel="modRibbon.GetEnvironment" />
                </group>
            </tab>
        </tabs>
    </ribbon>
</customUI>

Here's modRibbon:

Option Explicit
Option Private Module

Public Const ENV As String = "DEV"

Public myRibbon As IRibbonUI

Public Sub RibbonLoaded(ribbon As IRibbonUI)   'Callback for customUI.onLoad
    Set myRibbon = ribbon
End Sub

Public Sub Start(control As IRibbonControl)    'Callback to load main form
    frmMain.Show
End Sub

Public Sub GetEnvironment(control As IRibbonControl, ByRef label)    'Callback to supply the environment string
    label = ENV
End Sub

 

[RoryA]

Have you checked the option to 'Show add-in user interface errors' in Excel Options?

Also, I note you have both a label and a getLabel attribute...

 

[jjasmith4]

Have you checked the option to 'Show add-in user interface errors' in Excel Options?

Also, I note you have both a label and a getLabel attribute...

label indicates the initial text; getLabel indicates the callback that generates the label.
Are you saying you must specify only one, but not the other?

 

[RoryA]

Yes. Label is static, getLabel dynamic, and it can’t be both.