It appears that the one I have is more current so can the one I downloaded be what I need for this issue?
What you are seeing it's the version of the Addon Manager executable .DLL, it's normal your version is updated, since it's fetched from the internet each time you run any of the installers.
But the Stand-Alone Addon Manager installer contains OTHER files too, and those are the ones you need to update to fix this issue and, since they are NOT updated online, in order to get them, you have to download and install the Stand-Alone Addon Manager installer.
So, as I've said before, just download and install the Stand-Alone Addon Manager, and it will fix the issue.