Community ManagerWildstripe You don't need to use any launch command for Sims 4. It runs in DirectX 11 mode by default, and you can enable DX9 mode by checking the box in the graphics options. DX12 is backwards compatible with DX11, and DX9 is a standalone runtime that sounds like it's already installed on your computer and would certainly be compatible with a current system. (As an example, anyone running Sims 3 has to be using DX9, and the game doesn't require any steps beyond installing the runtime.) Memory Boost was previously only available in DX11 mode but is now active in DX9 mode as well.
Memory Boost can help prevent save corruption, and there are scattered reports of a save being unusable with Memory Boost off but still playable with it on. It's not a panacea though—there are definitely causes of save corruption that have nothing to do with what Memory Boost accomplishes. So I couldn't tell you whether it would help since I have no idea what's causing your particular issues.
