Show Add-in User Interface Errors

By default, if a workbook or Add-in attempts to manipulate the Microsoft Office user interface (UI) and fails, no error message is displayed.

However, you can configure Excel or any other Microsoft Office application 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 custom Ribbon tab appears without the desired number of controls.

To show add-in user interface errors

Click the File tab (in Excel 2010 or later) or the Office button in Excel 2007
Click Options
In the categories pane, click Advanced
In the details pane check Show add-in user interface errors
Click OK

Add-in user interface error reporting can be enabled from Ribbon Commander's Options menu

How To Trigger A Ribbon UI Error

The enabled Option setting can be tested by triggering an intentional UI error.

The split button control is composed of either a button or a toggle button, and a drop-down menu. Its icon and label on the split button come from the button or toggle button element. For more info, please click here.

Both elements of the Ribbon Split button should be defined, otherwise the control cannot be shown in the Ribbon.

The Ribbon Commander VBA code below demonstrates an incomplete split button declaration. The custom UI tab fails to display due to an Office Ribbon error.

The .ID text attribute cannot contain spaces

The .ImageMSO text attribute is case sensitive.
Spelling mistakes trigger UI errors

Public Sub CreateUI()
   
    With CustomUI
        .Clear
         
        With .ribbon.Tabs.Add(New rxTab)
            .ID = MAIN_TAB_ID
            .Label = MAIN_TAB_LABEL
            .insertAfterMso = "TabDeveloper"
             
            With .groups.Add(New rxGroup)
                With .Buttons.Add(New rxButton)
                    .Label = "Weekly Report"
                    .Size = rxsLarge
                    '> Valid: .imageMso = "CreateReport"
                    .imageMso = "Createreport"
                End With
            End With
             
            With .groups.Add(New rxGroup)
                .ID = "undo_group"
 
                With .splitButtons.Add(New rxSplitButton)
                    .Size = rxsLarge
                     
                    With .Button
                        .Label = "Test"
                        .imageMso = "Info"
                    End With
                     
                    '> Incomplete SplitButton triggers UI error ----------------
                    '> uncomment code below to display the control without error
                     
'                    With .Menu
'                        With .Buttons.Add(New rxButtonRegular)
'                            .Label = "Test-1"
'                            .imageMso = "Help"
'                        End With
'                    End With
 
                    '> ---------------------------------------------------------
                End With
            End With
             
            With .groups.Add(New rxGroup)
                '> spaces are invalid in ID
                .ID = "finance group"
            End With
             
            With .groups.Add(New rxGroup)
                With .Buttons.Add(New rxButton)
                    .Label = "Weekly Report"
                    .Size = rxsLarge
                    '> Valid: .imageMso = "CreateReport"
                    .imageMso = "Createreport"
                End With
            End With
             
        End With
 
        .Refresh
        .ActivateTab MAIN_TAB_ID
    End With
 
End Sub

Ribbon Control Limits

Similar to any other Excel feature, Ribbon controls are subject to max limits:

Max number of controls in a custom Ribbon UI: 10,000
Max number of controls in a custom Ribbon Group: 4,000

Office / Excel will not display any additional controls added beyond the Ribbon's max specifications: only the first 4,000 controls added to a group will be shown (without an error warning, if the 'UI error' option is disabled.)

Please enable 'UI error' messages during Ribbon development to ensure that Ribbon limits are not exceeded.

Max number of controls in a custom Ribbon UI: 10,000

Max controls in a custom Ribbon UI

Max number of controls in a custom Ribbon Group: 4,000

Max controls in a Ribbon Group

Max number of Buttons or Galleries in a Menu: 1,000
Max number of items in a Gallery: 1,000

If multiple Galleries are added in a Menu control, besides the gallery controls, every gallery item counts towards the 1,000 menu limit as well.

Caution: Custom Ribbon UIs with any of the errors shown below may not be appear in a custom ribbon.

UI error when more than 1,000 buttons are added in a Ribbon Menu

UI error when more than 1,000 items are added in a Ribbon Gallery

Control attributes are subject to limits as well. For example the ST_String has a max length of 1024 characters. It is applicable to button attributes such as: .label, .screentip, .supertip and .tag

Button definition: http://msdn.microsoft.com/en-us/library/dd926418(v=office.12).aspx

ST_String: http://msdn.microsoft.com/en-us/library/dd920439(v=office.12).aspx

PowerPoint Ribbon UI Errors

The error below may be shown multiple times, after clicking on a custom Ribbon tab of a presentation or PowerPoint add-in, if the custom images used in the XML code are missing from the customUI area.

You don't need to change your security settings or troubleshoot macros. All you need to do is import the missing images in the OpenXML PowerPoint file.

How To Show Add-in User Interface Errors

How To Trigger A Ribbon UI Error

Ribbon Control Limits

PowerPoint Ribbon UI Errors