iZotope have released an update, version 2.02 to Iris 2. This is a free update for registered users. Just go to the iZotope website and use your registered account email address to download the latest update.
Changes to Operating System Support:
Added Support for OS X 10.11 (El Capitan).
Added Support for Windows 10.
Fixed AU validation issue on OS X El Capitan.
Fixed an issue with dialog boxes not showing on OS X El Capitan.