There are two main ways to fix this depending on how you manage your mods.
Before downloading updates, you must know your exact game version number. Locate your SkyrimSE.exe in the game's installation folder. There are two main ways to fix this
Post your full skse64.log or f4se.log to a modding help subreddit or Discord, along with your game version (right-click .exe → Properties → Details). Post your full skse64
Before downloading anything, you must know exactly which version of the game you are running. You haven’t broken your game
If you’ve just launched your modded game and were greeted by a pop-up warning you about your , don't panic. You haven’t broken your game. This error is actually a "failsafe" designed to prevent your game from crashing to the desktop (CTD) due to a version mismatch. What is the "Address Library"?