Flex 2: Crash Bug in Canvas.measure

Here is a bug that’s been biting me for a couple weeks. Here’s a screenshot of Flex when it errors.

[COLOR=#810081]Screenshot of maddening error[/COLOR]

The program croaks when measureContentArea (in package mx.containers.utilityClasses, file CanvasLayout.as ) loops through the target’s children from 0 to target.numChildren. When the program errors: n == 1, i == 0, and target.numChildren is now 0, when it was 1 before the loop. target.numChildren has changed while the loop is running. It’s as if a child was removed by some side effect of calls in the loop.

This happens even when I have many IOComponents on the screen: [COLOR=#810081]Here[/COLOR]

This baffles me because I don’t see how I can debug it. I do add and remove and insert children in my game code, but unless ActionScript is threaded I don’t see how my code can reach into a loop in CanvasLayout.as .

The bug is consistent, but I am baffled.