Skyrim+skse+16640+2021 Link
To launch your modded game, you must always use the skse64_loader.exe file. It is recommended to add this as a non-Steam game to your Steam library for easy access. If you are using a mod manager like Mod Organizer 2 (MO2) or Vortex , you need to configure it to launch the game via skse64_loader.exe .
If you are choosing to stay on version 1.6.640, you must actively prevent Steam from updating your game to the newest version. Steam does not natively allow you to disable updates completely, but you can bypass this limitation. Method 1: Set AppManifest to Read-Only (Safest) skyrim+skse+16640+2021
This refers to Skyrim Special Edition version 1.6.640 (released September 2021) paired with SKSE64 build 2.0.20 (or later matching builds from late 2021). This was the last stable pre-Anniversary Edition update before Bethesda pushed the AE “free upgrade” (1.6.318–1.6.640 range). Many modders still consider this build a sweet spot. To launch your modded game, you must always