Re: Sims 4 : build mode crash
@Limou_Kpop As a test, please try playing in a clean user folder. Move the entire Sims 4 folder out of Documents > Electronic Arts and onto your desktop, and when you launch the game, a clean folder will spawn with no content. (Your saves and other content will be intact in the folder you moved but temporarily not read by the game.) Don't add anything to the new folder yet; just start a new save and let me know whether you can save your progress.
If that doesn't help, please run a dxdiag and attach it to a post.
https://help.ea.com/en-us/help/pc/how-to-gather-dxdiag-information/
Please also let me know what antivirus you use and if OneDrive is running on this computer, whether you use it or not.