Hi there,
from my testing it seems like the ArtemisLib causes the minecraft server to memory leak from time to time. Whilst ArtemisLib is installed I will eventually receive messages like: "The world xxxxxxxx (world) may have leaked: seen xx times".
!!The message can only be viewed in the /logs/debug.log and does not appear in the console!! It starts happening about 5 minutes after a player joined the world.
I assume you might have stored some references in the new entity attributes you are providing.
This causes a lot of problems, especially in larger mod packs.
I sadly don't have much else information about it.

I don't think I'm storing any new references in the attributes, but if I am, you're going to have to rely on @GiantLuigi4 to fix them, as I'm no longer updating the mod myseld

Huh, does this happen with just artemis by itself?
I can’t imagine what the cause would be. I’ve never really delt with memory leaks or anything like that.

From my tests it occured in a fresh server world with only the ArtemisLib (not even a mod using it) installed. So I'd assume it's being caused by the library itself, except there would be a unknown issue / unreported bug with the latest forge 1.12.2 version.