Customization drop down in Menu Maintenance 9.05.700

I am trying to deploy an MES customization following the instructions found on 10991ESC. As part of the sequence, under the Menu Maintenance program, I am supposed to select the customization from the Customization drop down. In my case, this drop down is grayed out and empty. I have made sure my customization does not have the WIP box checked and have no idea why it's not showing up.

Any ideas?

Tim