Re: Update won't let my game open. Running Yosemite 10.10.5

@thirstyslat If your hardware supports it you should upgrade to El Capitan (10.11) or newer. The release of The Sims 4 patch that came out today depends on macOS' Metal graphics layer. The first version of macOS that supported this is 10.11, AND Metal also requires that the GPU in your computer support it (the FAQ mentions what versions of the standard GPUs that Apple uses).

If you are NOT able to update to a newer version of macOS then you need to get the "The Sims 4 Legacy Edition" in the Origin client. Be aware that Legacy Edition will work with older macOS releases, but it disables all online functionality (Social media, Gallery, etc).