Once in a while, while debugging a Flex application, I have been show this error by Flex Builder.
C:\Program Files\Mozilla Firefox\plugins\NPSWF32.dll
Flex Builder cannot locate the required debugger version of Flash Player. You might need to install the debugger version of Flash Player 9 or reinstall Flex Builder.
Do you want to try to debug with the current version?
This essentially means Mozilla Firefox (if you have set FireFox as the default browser for loading applications from Flex Builder) can’t find the debug version of Flash player. I still haven’t found out the exact reason why it occurs. But, I have found solutions over time which tackle it. (I have always tried each solution, one after another, as sometimes one solution works in one case while the others don’t.)
- Copy NPSWF32.dll file from C:\WINDOWS\system32\Macromed\Flash to C:\Program Files\Mozilla Firefox\plugins.
- Download and reinstall the latest Flash Debug player.
- Install Flex 2.0.1 patch for Adobe Flash CS3 Professional compatibility if you are using Flex Builder 2.
- And if all fails, (sigh) just reinstall Flex Builder.