Latest 2.0.3+ version only works with Skript 2.6.1+ and was compiled in Java 17 (MC 1.13+). If you're running 1.7-1.12 or any Java versions that's not Java 17 use Skellett version 2.0.2, it has a zip of multiple possible versions to use. https://github.com/TheLimeGlass/Skellett/releases to view older versions.
Installation:
Place in your plugins folder
Restart server, and you have endless Skript syntax!
If you have any questions or need help with anything, feel free to reply in the discussion, and I will get back to you as soon as I can.