If you see the message "Something went wrong trying to install this application", re-install Air directly from Adobe at its site.
This link will take you to a website outside bbc.co.uk. The BBC is not responsible for content or software downloaded from external sites.
This message usually appears if you have a corrupted uninstall of previous versions of Air.
For further help you can Contact Us, or you can discuss this issue at the BBC iPlayer messageboard.