Flex Projects with older versions of flex are running without problem in Flex Builder 4,
because you can choose your framework in FB4. The 3.5 framework is integrated, if you use older frameworks, you have to download them.
I building a Flex 3.5 Application in my FB 4 right now.
But of course, you can't use flex 4 components in a flex 3.5 project!
Thank you for the info. That solves it.
1 person found this helpful
You can have Flex Builder 3 and Flash Builder 4 both installed at the same time.
Thank you Shongrunden.