For game version 1.6.640 , you specifically need SKSE64 version 2.2.3 . Using a newer or older version of SKSE will cause the game to crash on startup. How to Install SKSE 1.6.640 (Step-by-Step)
Do not download SKSE from third-party mod sites (e.g., Nexus Mods mirror) unless linked from silverlock.org. Only silverlock hosts the official, up-to-date builds.
Skse 16640 Link !!link!! -
For game version 1.6.640 , you specifically need SKSE64 version 2.2.3 . Using a newer or older version of SKSE will cause the game to crash on startup. How to Install SKSE 1.6.640 (Step-by-Step)
Do not download SKSE from third-party mod sites (e.g., Nexus Mods mirror) unless linked from silverlock.org. Only silverlock hosts the official, up-to-date builds. skse 16640 link