I have found recently that in order to 360Works plugins with FileMaker Server IWP (Instant Web Publishing) and XML they have to reinstalled in the proper folder on the FileMaker Server.
Mac OS X:
/Library/FileMaker Server/Web Publishing/publishing-engine/wpc/Plugins
On Windows the path is:
C:\Program Files\FileMaker\FileMaker Server\Web Publishing\publishing-engine\wpc\Plugins
You may have to create the “Plugins” folder.
Once installed, restart the server and you should be good to go.