
Skyrim bakes script data to save files and unisntalling the mod does not remove it. "You can't uninstall most mods from ongoing game. If you removed scripted mods from ongoing game, then you will have to start a new game." - Ilja That tool cleans obsolete entries and orphaned scripts from the game, but script data will remain in the save file, causing Papryus to constantly check it and creating errors. This includes work done with Save Script Cleaner. There is no such thing as a clean save, when mod is removed. "You can't remove mods from ongoing game. Unofficial Skyrim Legendary Edition Patch by Unofficial Patch Project Team. If you started a new game with 10 mods installed, you're going to be stuck with those 10 forever." Bethesda's own developers have confirmed the only way to properly remove a mod is to load a save made BEFORE that mod was introduced into the game.

Doing this repeatedly WILL damage your save and WILL eventually lead to it becoming corrupt and unusable. You cannot remove any mod, not even the patch, without there being some data that's been permanently changed. It does not matter who tells you there is, it doesn't exist in Skyrim.
