Cannot Open Expansion packs installers

Hello games4theworld!

I am just new here and I desperately need your help. I have been having problems with opening the installers (.app) for Seasons and Master Suite Stuff. I already downloaded the ultimate fix for the base game but since I have to install at least one of the expansions pack to work, I have to install these first, the installers won't launch every time I would try to open it. I have already set my Preferences to allow any app to run but I just can't seem to open it.
 

I guess you are trying to launch the .app that is inside the rar ?
You'll need to mount it first. All the steps are explain in this pdf : http://games4theworld.org/Guides/Sims_3_Mac_Guide.pdf