Grab the .7z file from the link above.
(or higher within the 2.2.x range specifically labeled for 1.6.640). Installation Overview Extract Files : Download the 7z archive and extract its contents. Move to Game Folder : Copy the files (specifically skse64_1_6_640.dll skse64_loader.exe ) directly into your Skyrim Special Edition main directory skse 16640 link
Title: Keeping Your Load Order Stable: The Complete Guide to SKSE 1.6.640 Grab the
Always launch Skyrim using skse64_loader.exe . Add it as a non-Steam game if desired. skse 16640 link