Sometimes when you “Run” a project in FB, a dialog box appears telling you that “your FlashPlayer version is not updated…..”, usually the first line of this message will tell you exactly where this “FlashPlayer” is located. Notice that this differs, probably, among different versions of FB, or different project settings – this, I don’t know much about so I’d very much appreciate it if someone can fill me in on the details 🙂 – anyway, in either case what you need to do is to upgrade your FlashPlayer.
First go to this page: http://www.adobe.com/support/flashplayer/downloads.html and get yourself the most recent “Plugin content debuger” and/or “Project content debugger”.
The “Plugin content debugger” can be run from anywhere, and it will install the new FlashPlayer, which FB can use.
The “Project content debugger” is actually an executable file of FlashPlayer itself, and it should be put in a certain folder on your computer. The aforementioned dialog box should tell you where it is. This folder is supposed to contain a file called “FlashPlayer.exe” already, so what you’re gonna do is to rename/back it up, then cut and paste the “Project content debugger” file into this folder and rename it into “FlashPlayer.exe”.
Now you can run your FB project normally!
This is intended for new Flash Builer users, and also for me when I get older and… probably go senile, haha. Hope it helps.