While working on a fairly large pure AS3 project, I wasn’t able to export a release build. Well, it was more like, Flex Builder 3 just gave up and didn’t even give me an error. Another issue I ran into: Running the debugger on a project….and….it…..takes……

FOREVER

…..then

FAILS

right in your face.  (Was I expressive enough with the big cheesy font in red?) You check your flash version, you get the latest debugger, nothing works. What worked for me:

Clean your project! Project->Clean…

Then pick the project you’re currently working on. Always seems to work for me. Hope it helps someone out there.