The Sims 4 fails to launch when Custom Content is present in Mods folder

KitkuSopilcaUwU​  Please download a fresh copy of one cc item and see whether adding it crashes the game.  If it does, remove your Mods folder (even though you've emptied it out), open the game to generate a new folder, and try the new cc again.  If the game still crashes, download a different cc item using a different browser, just in case your main browser is breaking the files.  For example, sometimes the browser is set to try to open files, which can damage them.