I just had a weird one I thought I’d share on here in case anyone else has it. Or in case I get it again for that matter. I kept getting the same error from Flex Builder :
“An internal build error has occurred. Right-click for more information.”
After much searching and sulking I found the culprit. It was an swc file with a MovieClip in. It turns out that the animator had left a blank keyframe in there. And the blank keyframe had a motion tween on it. Get rid of the tween, and it all works fine.
I suppose I should submit it as a bug but I’m a bit busy right now… :-S