There was a change in r141 to the way strings are compared.
Like naelian says, you're running the actions in event 107 way more times then necessary. In tutorial level when the 'Pulse' animation finishes, event 107 runs 26 times. That's 26 * 13 objects * however many instances of each that need to have their animation set. The animation name is "Default" and you're setting it to "default" (lower-case 'd').
The code that compares strings to see if "default" == "Default" needs to be called hundreds of times in 1 tick. In r139 it was fast so you didn't notice it. In r141 it was changed and it freezes up (in Chrome only?). You'll see if you set the animation to "Default" instead of "default" there's no freeze.
Here's a simplified capx that highlights the problem: setAnimationCases.capx