The Sims 2 and Sims 3 EA Activation Error

I think puzzlezaddict is probably correct that it's a parallels issue. Maybe someone will see this and have better advice then buy another machine, because I know not everyone can do that. And your idea of cheap and my idea of cheap may not be the same.

I used parallels with Sims 2 at one point, but it was with Ultimate Collection. I didn't have any issues, but I didn't like switching between partitions and ended up buying a cheap machine to run Windows instead. It's just an AMD Ryzen processor that my husband mounted to the back of one of my monitors on my desk and Sims 2 is pretty much the only thing on it. Having separate machines/monitors has other benefits too. I bring up Sims 2 or reference images on the Windows machine on the left monitor, then I open Sims 4 on my Mac on the right monitor and I can build easily that way. The one downside to my setup is I do have to use Synergy to go between monitors/machines with the same mouse and keyboard and that's not a free program. Without it, I would have to use a different mouse and keyboard for each.

Swisss_Chocolate​  This sounds like it might be an issue between the EA App and Parallels.  I haven't seen any other reports of this in the last couple days on dedicated Windows systems, at least.  But if you want to check, you could download the Sims 3 base game on your Mac and see whether it starts.  It's not that large by itself, 7.75 GB on my Mac, so hopefully it's not a burden to install.