Here's an update...
I've looked for every Flash Player and Debugger I could find in the Adobe Flash CS5, Flash Builder 4 and seperate Flash Player folder and deleted them from my computer. Then I reinstalled Flash Player and installed the following debugger:
After that I tried Flash Builder again and was able to test my project, though it opened Flash CS5 instead of Flash Player, very strange.
So I continued with the debugger and that also started the Flash CS5 player instead of the standalone player and also started loading in Flash Builder:
Up till the point where Flash Builder showed me this error:
The current problem is now the error above and the fact that I can't seem to be able to see any traces of debugging code in my console (Flash Builder) or Output screen (Flash Pro CS5).
Has anyone got an idea?
I was able to make it work IF I let Flash Builder Generate an HTML Wrapper file.
If I tick it off, the debugging will start Flash Pro CS5, but doesn't debug and gives me the same things as the 2 last screenshot.
If you do not generate an HTML wrapper, Flash builder tells the OS to open a SWF file. The problem with this is that the debug standalone player has to associated with SWF files in Finder (Get Info on a swf file, open with).
This has been addressed in Flash Builder 4.5 where you can specify which standalone executable to run.