Posted on EA Help, The Sims 4 will be ending their support for 32-bit and Non-metal MAC OS systems this June (2019). If you are stilling playing on a 32-bit or Non-metal MAC OS, you will still be able to play The Sims 4, you just won't be getting any updates, view the gallery or buy any of the new packs that will be coming out. EA will be offering a Legacy Edition of The Sims 4 for those who wish to continue to play but can not upgrade their systems to 64-bit or Apple's Metal.
More information on this announcement can be found here.
If you do not know what type of system you have, 32 or 64-bit on Windows (PC), go to your Windows home (menu) button > right click and select System from the menu
On the next window that open look at Device Specifications and then at System Type
For MAC systems go here to find your machines system type.
You can also go here to find out if your MAC system can be upgraded.
You can go here to learn how to upgrade your Windows 10 32-bit PC to 64-bit.
If you are still using a Windows 7 32-bit PC, I would recommend looking into upgrading to Windows 10 as Microsoft is ending support for W7, but if you can not upgrade, go here to learn if you can upgrade your machine from a 32 to 64-bit.