Unable to add ItemType to TOC

Hello,  I'm having trouble adding an ItemType to the TOC. I am not getting the same results as the tutorial "Basic Admin Navigation." From the ItemType (editting) dialog box for "MyNewType" I do the following:

MyNewType > TOC Access (tab) > Pick Related (from dropdown)> New

Nothing happens when I click "new." I cannot add anything to the list. If I select "Create Related" from the drop down, then I can create a new entry for TOC Access. However, I want to give access to existing Identities. I want to give "Administrators" access. It seems like there may be a bug?

I'm using Aras Innovator v10 on Windows 8.1 via Firefox.

Thanks for the help!