I was struggling for several hours trying to get the debugger to connect to my simple FDT5 mobile app, testing it on Android.
I could not find anything on the Internet that solved my issue, and I was sure I was running the debugger Flash player. What’s more, I was able to connect to the debugger using Flash Builder 4.5, so I thought it had to to with Windows Firewall, or maybe Symantec blocking port 7935, or something.
It turns out that in my project (Android) manifest, I did not request Internet access for my simple app. When I selected that, then the debugger connected fine. I don’t know if that qualifies as a bug — why should an app have to have internet access for debugging? Anyway, I point it out in case someone else is searching on this same problem.