Constant lags despite high end PC.

I'm also experiencing this issue. The camera is choppy/lagging when I play on my old save, but it's smooth when on a new save. The sims movements are smooth; it's mostly the camera that is extremely choppy when moving around the world. I've tried repairing the game, but there's an issue where I can't repair Enchanted by Nature because I "don't own it" when I do. I cleared the cache, deleted unused Sims from the save file, removed mods, and cleaned out most of the inventories. 

This started after I updated the game to the latest patch and downloaded Enchanted by Nature. My game/save ran perfectly smooth right before then. I really hope that this is a fixable issue, for I would hate to have to recreate this save to resolve the poor camera performance.