Re: white screen after clicking new game/load game.
@shilan00durmush You'll need to test your mods and custom content in the new folder before adding back your saves. It's very likely that something in your Mods folder caused this error. Start here for mods known to cause this particular issue:
And this is a longer list of mods and cc that are known to be broken:
For anything else, you'll need to test it manually. Once you've done that, you can move the contents of the saves and Tray folders to the new Sims 4 folder, plus Screenshots and Recorded Videos if you care about those, plus UserSetting.ini for the login rewards. The rest can be discarded.