Right-click and there is an option to "Show Hidden Members"
This makes no sense at all to hide add-ins. It makes it difficult to troubleshoot. My login to Vault button was missing. The first thing I did was confirm that the Vault add-in was loaded and looked through the list for others.
Then I spent 3 hours repairing and uninstalling Vault Pro2013 and Inventor 2013 and rebooting. I accidentally righ-clicked on the add-in list and found the option to "Show Hidden Members". Then I saw the "EDM Addin"
Thanks Autodesk, for wasting 3 HOURS of my life for something that I should have figured out in 3 minutes!!!!