urgent!flexSDK not working

hi everybody,

i downloaded a code from http://www.neave.com/dandelion/

and i wanted to make few changes on it. But when i opened the main.fla file in flash and tried to play movie(ctrl+enter)

This warning appears:

so i´ve downloaded the SDFile from here:

http://opensource.adobe.com/wiki/display/flexsdk/Flex+SDK;jsessionid=D5A7CBE6ABBFD34BF8324C222B106FAA

but its still not working:(

can anybody help me where can be the problem?

really really thanks!