That is weird. What location did you download from?
from the link you provided here in this forum.
It just opened now, thanks for responding. Here's a screenshot prompting me to update -
You are asked to update because you downloaded Creator 1.3.1 and the latest is 1.3.3
Download the update: http://cocos2d-x.org/filedown/CocosCreator_v1.3.3_mac