compiling with Flex 4.0 gives flash.desktop.NativeProcess could not be found

I have an ActionScript only Flex project that was written by someone else. I know it was compiled successfully for Air 2.0

I can compile this project using Flex Hero and with <application xmlns="http://ns.adobe.com/air/application/2.6"> - however, my air file will install only on windows (on mac i get a weird 'installation file is corrupt, contact the author' error message).

So now I want to compile it for Air 2.0 as it was originally written for. So i change the used Flex SDK from Hero to 4.0 and change the target air version to <application xmlns="http://ns.adobe.com/air/application/2.0"> - but then i get three compilation errors:

Description Resource Path Location Type 1061: Call to a possibly undefined method openWithDefaultApplication through a reference with static type flash.filesystem:File.

Description Resource Path Location Type 1172: De开发者_高级运维finition flash.desktop:NativeProcess could not be found.

Description Resource Path Location Type 1172: Definition flash.desktop:NativeProcessStartupInfo could not be found.

but I read that these features were introduced with AIR 2.0 - so how can't I compile if I change the SDK from Flex Hero to Flex 4.0? (i'm using flash builder 4)

I guess Flex 4.0 comes with an older version of AIR (< 2.0).

What you have to do is download the AIR SDK 2.0 and unzip it to the Flex SDK folder.

Older versions of AIR SDK can be found here