[UPDATE: Thanks to Matt, I've added in OSX paths to the Flash Players.]
For those folks who have upgraded to Adobe Flash CS4 and also installed FDT 3 as your editor, you would have realised that when you create a new Flash project in FDT, there will no longer be a Flash_CS3 language type in the Project Language drop down. It is missing by default, but in this article, I’ll go through with you on how to get those much needed project languages back into your FDT development environment.
Step 1:
In your New Flash Project dialog, click on the “Configure defaults…” link button.

Step 2:
That will lead you to the Core Libraries dialog panel in Preferences, which you can usually access via the menu:
Window > Preferences… > FDT > Core Libraries
First, click on the AS3 Core Libraries tab, and then click on the Add button.

Step 3:
The Core Library dialog is where you will create your new core libraries. Choose Flash CS3 for type, and give your core library a name. In my case I gave it “CS4_FP9″, which stands for “Flash CS4 using Flash Player 9″. Of course, you can give any fancy name that you want.
To proceed in choosing a path variable for your core library, click on the Browse button.

Step 4:
Now the Link Libraries dialog will be opened, and it is here where we can choose which library to be used for the path variable. Click on the “New…” button.

Step 5:
This is the final step. In the New Variable dialog, first give a name for your new variable. I chose to use the same convention when naming the core library, which is “CS4_FP9″. Again, it is up to your own fancy in giving it a name. In the Location field, click on the Folder button and browse to:
Windows XP: C:\Program Files\Adobe\Adobe Flash CS4\Common\Configuration\ActionScript 3.0\FP9
OSX: /Applications/Adobe Flash CS4/Common/Configuration/ActionScript 3.0/FP9
If you are working on Windows Vista or Mac OS, please kindly let me know the path by leaving a comment below. I’ll update this post thereafter. Thanks.

That’s it! You’re done! Well almost if you ask me. We do want to be able to use Flash Player 10 in our projects too right?
Click on all the OK buttons but stop when you are back in the Preferences dialog box. From here, repeat Step 2 to 5. The location for the Flash Player 10 swc is in:
Windows XP: C:\Program Files\Adobe\Adobe Flash CS4\Common\Configuration\ActionScript 3.0\FP10
OSX: /Applications/Adobe Flash CS4/Common/Configuration/ActionScript 3.0/FP10
Done!
After finishing the above, you can now truly click on all the OK buttons to get back to the New Flash Project dialog, and see that you can now target the correct Flash Player while developing with FDT. Happy coding!

























good article, when i first switched to CS4 i was wondering where this stuff was and i just ended up using the Flex SDK which seemed to work fine.
Here are OSX paths:
FP9: /Applications/Adobe Flash CS4/Common/Configuration/ActionScript 3.0/FP9
FP10: /Applications/Adobe Flash CS4/Common/Configuration/ActionScript 3.0/FP10
Many thanks Matt!
thanks so much for the excellent tutorial. all the others i found assumed i had been using FDT for a while now, but i’m new so this was perfect. thanks again!
@Jeremy I know how you feel man. Went through that before. Glad this helped!
I just set this up for the Mac OS X, so easy thanks so much!
I’m new to FDT, and hoping that it might be possible somehow to use directly to FDT to publish CS3 .fla’s to Flash Player 10… ? Perhaps using an ant build path? Can anyone answer this for me please?
Great job, thank you for sharing.