The Plugins page is divided into two sections:
PLUG-INS INSTALLED: Lists all installed plug-ins for the version selected in the Wwise Version list. For each plug-in, there are two associated menus:
The documentation menu, which includes a More Info link to the website overview of the plug-in, as well as links to any other plug-in documentation.
The settings menu, which includes an Open Containing Folder option, which opens the installation directory in Windows Explorer or Mac Finder, as well as an Uninstall option.
INSTALL NEW PLUG-INS: Use one of the options to install premium, partner, or community plug-ins.
Add Plug-ins: Installs Audiokinetic premium or partner plug-ins through the Launcher. Click to open the CHOOSE PLUG-INS page.
Add from directory or Add from archive (list selection): Installs community plug-ins, which you must download separately. Click either of these to open Windows Explorer or Mac Finder and navigate to the location of the third-party plug-in in order to install it. If the plug-in package is already extracted from its .tar or .zip archive, use the Add from directory option. If the plug-in package is still in its .tar or .zip file, use the Add from archive option.
For more information, refer to Installing Community Plug-ins.
As indicated in the Wwise Release Notes, each version of Wwise is only compatible with certain versions of a plug-in. If you attempt to install a plug-in and receive a "Cannot Install Plugin" error message, then it is probably incompatible with the selected version of Wwise or is otherwise packaged incorrectly.