Few random things I'd try..
First, are you running this in debugger? (CTRL+SHIFT+ENTER)? If not then use that means of executing and put some breakpoints in the code so you can watch the code execute step by step to see what's generating an error. In publish settings for this SWF in the SWF parameters make sure you check to permit debugging to get more verbose errors:
Explicitly including ExternalInterface rather than flash.external.*;. It should include it (and everything in the package) but I've had lookup issues with this before. So:
import flash.external.ExternalInterface;
See if that clears up the break on that line. You should set a break point above that line however so you can step into the command and watch for errors.
Make sure your access toggle (network/local files) is correct to access your RSL.
Sometimes a couple more lines of code for clarity can help a lot. Break up your getDefinitionByName line into 2 lines, maybe adding in a condition just so you can step through it and analyze exactly which part of that compound statement is going wrong. It could be as simple as your "new (...)" isn't being cast to a Sprite before you assign it so the line fails. So try:
var test2Class:Class = getDefinitionByName("ConnectionIcon_Orange") as Class;
if (test2Class)
{
var test02:Sprite = new test2Class() as Sprite; // cast
}
By stepping through it you'll see if your definition cannot be found (RSL or link issue) or if assigning it to a Sprite (test02) is the issue (perhaps it's a MovieClip or some other unexpected type and this fails).