Re: cant save, no buy or build mode
@hippieswag1 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 see whether these issues are still present..
If that doesn't help, please let me know what antivirus you use, and whether OneDrive is running on this computer.