Supernatural Installer Wont Star

Downloaded the supernatural expansion, but when I click on the installer it appears in the dock for half a second then disappears. Help!

Did you use Stuffit Expander to unzip your file?

Consult this post:
https://games4theworld.forumotion.com/t7248-how-to-install-sims-3-with-or-without-ep-s-on-mac-dmg-creating

for what ever reason make sure you use stuffit expander the reason why I personally do not know... but in anycase make sure you use stuffit expander then turn it into a mountable dmg via disk utility these are required