To workaround : Open a Terminal window (Click the Launchpad icon in the Dock, type Terminal in the search field, then click Terminal).
Then enter the following two commands. (Admin Rights Required)
cd /Library/Frameworks
sudo xattr -r -d com.apple.quarantine ./Adobe\ AIR.framework
Use the password that you use to logon to your Mac when prompted.
Note that your password will not show any feedback, so just press 'Return' at the end.
Adobe Air should now be out of quarantine and installable.