From now on, do not launch Skyrim through Steam. You must run skse64_loader.exe to start the game with mod support. Why version 1.6.640 is a "Golden Build"
Grab the .7z file from the link above.
For troubleshooting, refer to the or the r/skyrimmods community guides. Always verify your game version in Steam ( SkyrimSE.exe > Properties > Details) before downloading SKSE. skse 16640 link
Installation is straightforward—manually dropping the .dll and .exe files into the Skyrim root directory remains the gold standard. Compatibility & "The Version Trap" From now on, do not launch Skyrim through Steam
Inside the SKSE archive, there is a Data folder containing scripts. Copy the Scripts folder from the archive and merge it with the Data folder in your Skyrim directory. For troubleshooting, refer to the or the r/skyrimmods
The number "16640" refers to a for Skyrim Special Edition (1.6.640), not an SKSE version number. The correct SKSE for game version 1.6.640 is SKSE 2.2.3 (or later builds).