Autotune 4 shows up as a directx plug-in.
Here is a fix thats floating around, this needs you to edit the registry, don’t if you aren’t sure what you are doing(you are on your own)
1) Close Adobe Audition
2) Open the registry by going to the Start menu, selecting Run, then typing regedit and clicking OK
3) Under HKEY_LOCAL_MACHINE,
go to the key \SOFTWARE\Adobe\Audition\PlugIn\DirectX
4) Locate the data item whose Name is {02A06B08-744E-40E3-8B78-E45D71750DC8}
5) Delete that item
6) Close the registry
7) Run Adobe Audition
8) In the Edit view, select the menu item Effects -> Refresh Effects List
Auto-Tune 4 should now appear under the DirectX tree in the Effects list