Seems that the release from the Online Content discovery only contains luasocket for linux. On Windows, I get this error:
ModError: Failed to load and run script from C:\Users\<user>\Downloads\minetest-5.5.1-win64\minetest-5.5.1-win64\bin\..\mods\minetest_presentations\init.lua:
error loading module 'socket.core' from file 'C:\Users\<user>\Downloads\minetest-5.5.1-win64\minetest-5.5.1-win64\bin\..\mods\minetest_presentations/external/socket\core.so':
%1 is not a valid Win32 application.
Seems that the release from the Online Content discovery only contains luasocket for linux. On Windows, I get this error: