This is running Win8 64bit (on iMac-bootcamp)
1.open the HTML file that already exists.
2.use the code panel, add the any event to the stage(ex: Stage-Event-creationComplete).
I guess, the existing HTML has no "#Stage" div.
so, when I try to add the events to the stage, EA is crashed.
Yes indeed, looks like a bug - thanks for the report, Ume!