I downloaded the legacy edition for my Mac. I moved over all my files from my original sims folder to the legacy edition. It worked great. all my saves were back... I was happy.
A week later I logged into origin and it updated my Sims game. Now my game is back to basics. no saves, no library nothing. I no longer have a sims folder only the legacy folder. I have repaired, uninstalled, and done everything I can think of. My saves are still in the legacy folders where they were previously.
Has this happened to anyone?
You only need the Legacy Edition folder if you are running Legacy as far as I am aware. Are you using iCloud? Please check, instructions here - https://bluebellflora.com/2017/02/06/sims-3-and-sims-4-not-loading-save-games/
Using CC/Mods is at your own risk, EA are not responsible for making the game compatible with 3rd party content, the creator is.