I've re-downloaded the file multiple times from Adobe's website, even gone back an installed the current AIR version and still get this error both during install and attempt to run it. (Yes, have also deleted the installed App, emptied trash and attempted the install again from a freshly downloaded zip.)
So what am I missing?
I gather you're on a Mac. DE is not running under Lion....
I'm running Lion. I found it didn't work (same error as you) if I just dragged the app into the Applications folder, but did work when I installed it from the package.
I hit the info button above on that dialogue and this is what came up:
"The app’s authorization has been revoked
Although this app was signed by an identified developer, the certificate for the app has been revoked. There may be a problem with it. The app cannot be opened.
You should check with the Mac App Store to see if there is an updated version of this app, or check with the software developer."