[AccessD] Ribbon customization failing to show my tab

Access ribbon customization.

The instructions are pretty straightforward here, so I thought I would get a
ribbon at the end of the attempt. I created a USysRibbons table, the columns
are
ID		RibbonName		RibbonXml

The XLM was pasted exactly as shown here:
https://support.office.com/en-ie/article/Customize-the-Ribbon-45e110b9-531c-
46ed-ab3a-4e25bc9413de#bm2

In the database options I have selected MyRibbon from the list of
customizations.

Result:  Nada.

Am I missing out on some key step? Is the XML invalid? Is the fact that I am
using Access 2013 and this schema is for 2007 a problem? Do I need to load
some other file some place?

<customUI xmlns="http://schemas.microsoft.com
/office/2006/01/customui">
 <ribbon startFromScratch="false">
 <tabs>
 <tab idMso="TabCreate" visible="false" />
 <tab id="dbCustomTab" label="A Custom Tab" visible="true">
 <group id="dbCustomGroup" label="A Custom Group">
 <control idMso="Paste" label="Built-in Paste" enabled="true"/>
 </group>
 </tab>
 </tabs>
 </ribbon>
</customUI>