Before Continuing:

• Check you are using the latest version of the mods and its dependencies
• Always include a latest.log if you are crashing
• Remove known hacky mods such as: Optifine, Fabric API/Connector on forge, and every kind of hybrid server like Mohist and Velocity. None of these are supported. Also try without other lesser usual suspects like Sodium and Lithium.
• If you are unsure which mod is the culprit.
  Disable all of your mods and enable them 1-2 mods each time to isolate the culprit
• Confirm that there is no existing issue with a similar description submitted in the list of issues.

Version

1.20.1-FORGE

Supplementaries Version

supplementaries-1.20.1-3.1.37

Moonlight Lib Version

moonlight-1.20-2.16.5-forge

Describe Issue

Empty cage items currently stack up to 64, despite being intended to stack only up to 16. This is probably due to the CageItem class inheriting AbstractMobContainerItem#getMaxStackSize, which forces the stack size of empty cages to be 64 in spite of the item properties given during registration.

If I'm not mistaken this should be fixable by just adding an override for getMaxStackSize in the CageItem class, but I don't have a dev environment for Supplementaries set up to test this out.

(I've also tested on 1.21.1 NeoForge using supplementaries-1.21-3.4.4 and moonlight-1.21-2.20.7, same bug occurs here as well)

done