This project is abandoned and its default file will likely not work with the most recent version of Minecraft. Whether this project is out of date or its author has marked it as abandoned, this project is no longer maintained.
Slimefun 4 newest version but now you are able to use it in your Aternos server.
Please support the actual creator, this is just a reupload to everyone be able to use it in Aternos since the original one has ended...