You're welcome!!
I don't know if this will work for those using the EA App, but wanted to share anyway, just in case it does help.
When I download .Sims3Packs I do so to a temporary folder on my desktop, and either double-click them to install automatically. Or if there's more than one, then copy them to the Sims 3 downloads folder (C:\Users\Username\Documents\Electronic Arts\The Sims 3\Downloads)
Open the Sims 3 launcher, go to the downloads tab and select both files and install. Look in the Installed Content tab to see what was installed.
That seems to help. However, I am using the disc version of Sims 3. Downloading and installing .Sims3Pack files seem to work slightly different with the disc version for some reason.
Edited to Add: This does not work for players using the EA App, most likely due to the miss-communication going on between the EA App and the Sims 3 launcher.