Debugging Flash Through a Browser

Flash is great, until you have to debug it through a browser. Maybe you’re trying to load images across the net, or you’re scraping an XML feed? Either way, trace doesn’t work, so you’re stuck with nonsensical error messages. Check out some simple tips/tools that will make debugging a less painful experience. There are two tools you need to make your life easier.

1) Flash Debug Player – Get it here: Download Flash Debug Player

This player pops up a window when you get a badly coded flash file that kicks out an error. You’ll be surprised how much shoddy flash coding there is kicking around the internet.

2) You NEED Firebug: Download FireBug & FlashBug

It’s criminal this tool is a free add on for FireFox. It’s a suite of tools that lets you debug javascript, inspect coding elements, view CSS, scrape post variables etc. In fact, if it’s web based, chances are FireBug can do something with it. You then need to download FlashBug, which is basically a plugin for FireBug which allows you to view flash messages. You can use “trace” again, and actually see what’s going on in real time, IN YOUR BROWSER. First time I used this tool, it brought a little tear of happiness to my eyes 😉

If you use these tools, PLEASE CONSIDER DONATING!! These are excellent tools provided by surpemely talented coders. Whilst they don’t demand payment, even a few bucks/pounds/euros makes a difference. Chances are these tools will save you time/your sanity, so share the love 🙂 Adobe, should really have provided something like this with Flash, but thankfully these guys have come to the rescue.

After you’ve downloaded these tools, you may need to configure your mm.cfg file, but that will depend what OS you’re running and your system security. If you’re stuck post a message/comment and I’ll see if I can help you out.


Windows Users – If you have UAC turned on, you may need to turn it off until you’ve got FlashBug set up and working. The mm.cfg file is hidden away in your user profile and will be write protected.

Trace  – Thanks to FlashBug, you can trace out all kinds of information (and actually get to see it). If you’re using a lot of classes, I’d set up a simple error class which allows you to attach the class name to your trace message. That way you know where your error message is coming from.