It doesn't work on 1.21.3
in the source code was not allow this plugin work on this version

seems to be an issue with paper specifically, works with spigot

Since I don't have the time for testing, please feel free to try this build, absolutely no guarantee.

latest.log
it throws an error when trying to run it.

Dev just send the plugin straight to 1.21.4 and call it a day!

latest.log it throws an error when trying to run it.

Ah, forgot that we are also using Sounds in this plugin :D
well this should fix it. https://ci.pcgamingfreaks.at/job/Minepacks/397/artifact/a/Minepacks-2.4.31.5-SNAPSHOT-Release.jar

looks good, will add another comment if any issues arise