So, I love CC. However, with the Sims 4, I'll often try to download something, the download popup thing will suggest I open it with SimPE (which I still have installed because I still play the Sims 2 ...
You're just getting your file formats confused and then doing it wrong. Note that the download is .package - package files don't get opened, at all, unless you are trying to edit the contents. Package files just get dropped into the Mods folder as they are. :)
You would only need to open the download in WinRAR if it was a .RAR file. (Or optionally .zip, although Windows can handle .zip files just fine.)
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