Flex / ActionScript: Debugging causes Firefox to crash

After an update to Firefox 3.6.6 I've noticed that while debugging Flash it would crash and display "The Adobe Flash plugin has crashed". It turns out it's due to a new feature called "Hang Protection" that allows Flash to run in it's own sandbox and not take down the whole browser when/if it crashes. After 45 seconds the browser will close Flash because it thinks Flash has stopped responding.

Hang Protection can be turned off so debugging with Flex Builder / Flash Builder will work properly. Follow the directions at this url.

NOTE
Firefox 4 requires a change to a different property. Use about:config to alter the behind the scenes settings and look for dom.ipc.plugins.timeoutSecs and set it to -1.

Flex: Switching the debug default browser

I've started working in Flex quite a bit now. One of things that has bothered me is Flex always launches a debug window in Internet Explorer. I've been having some problems with the browser and would like to use something different, but couldn't figure out how to switch it. Someone showed me how this morning.

1) Goto Window => Preferences

2) Goto General => Web Browser

3) Select the browser you want to launch in the "External Web browsers" window.

Now your debug session should launch in your browser of choice.