@Superhero345 GraphicsRules.sgr lists all the game's graphics categories and specifies which setting should apply given the user's hardware or in-game settings. For example, the in-game Sim Quality setting you choose determines at what distance the game switches between higher and lower levels of detail for sims, along with a half-dozen other values.
The GraphicsRules file is located inside the game's program files, specifically in [install location]\The Sims 4\Game\Bin in Windows. You can open it in Notepad if you're curious; use ctrl-F to search for keywords, or just scroll through.
If you place a copy inside ConfigOverride, it will override the original. This is a way to change the settings to what you like in a more granular way than you can accomplish just by fiddling with the in-game graphics settings, AND to preserve your changes after a repair or update, either of which reverts the version in program files to its original state. However, GraphicsRules is occasionally updated for new content, but only the original file. So if you have a copy in ConfigOverride that gets outdated, and you don't replace it as well, it can cause all sorts of problems.
Point is, remove this file, and either make yourself a new version from the current one in the game's program files, or wait for whoever made this one to update it for the current patch.
