Branched this to a new discussion as this is not related to the Adobe Download Assistant and a blue screen in Windows.
Gregoryhel which Mac are you using? There has been reports of users turning off the Automatic Graphic Switching option in the Energy Saver preference pane to allow AIR applications to function. This would include the Adobe Download Assistant.
I am using an i7 macbook pro from early 2011. I have tweetdeck (an air app) working just fine. but I will give that a shot.
UPDATE: in system preferences >> Energy Saver, there is no "automatic graphic switching" option to turn off.
My understanding is the most recent Tweetdeck no longer utilizes Adobe AIR. From the time period you purchased your Mac it probably is the Graphic Display switching issue. Just in case though you might also want to try the steps listed in Troubleshoot AIR installation | Mac OS. Feel free to respond to this thread if you have any questions about the listed steps.
I installed http://codykrieger.com/gfxCardStatus and disabled graphics switching and the adobe download assistant still did not function.
One would think that a software company such as adobe would make an application that does not require a large segment of users to go in and fiddle with settings just so that they can download a trial version of adobe software. This is really lame.
Gregoryhel that is odd that you did not see the option in your Energy Preferences and had to use a third-party utility to affect the change. Do you have the option under Graphics of Better Performance or More Battery Life then?
We are currently working closely with Apple to rectify the issue.