Sims 3 World Adventures Installer Not Working

Hello,

I'm currently having trouble opening the Sims 3 World Adventures Installer. When I click on it and open it, it then opens with a message saying "Could not verify the integrity of the installer." 

I haven't placed the whole expansion file anywhere special since in the instructions on this site, it just said to install any expansion we want.
I hope I can fix this and thank you for taking a look at this topic!

Hello, and welcome to the forum, 
sorry to hear about your problem. Maybe this guide will help you.