This update added permissions. Players with OP permissions are granted all permissions by default.

Parent Permissions These permissions grant groups of child permissions.

• viewinventory.see

Grants permission to view both a player's inventory and their ender chest. (Includes inventory.see and enderchest.see)

• viewinventory.edit

Grants permission to edit both a player's inventory and their Ender Chest. (Includes inventory.edit and enderchest.edit)

Individual Permissions Use the following nodes to configure features individually.

• viewinventory.see.inventory

Enables viewing another player's inventory using the /vi inventory command.

• viewinventory.edit.inventory

Allows editing another player's inventory within the opened GUI. Without this, the inventory is read-only.

• viewinventory.see.enderchest

Allows viewing another player's ender chest via the /vi enderchest command.

• viewinventory.edit.enderchest

Allows editing another player's ender chest within the opened GUI. Without this permission, ender chests are read-only.

The item disappearance bug was primarily caused by two processes competing with each other.

1. The process of updating the GUI display (copying the target player's inventory to the GUI)

2. The process reflecting click actions (copying what the viewer clicked in the GUI to the target's inventory)

When clicking rapidly, process 1 would overwrite process 2. This caused the GUI to revert before changes were saved, resulting in items disappearing.

Solution

To eliminate this conflict, we fundamentally changed the approach.

Prioritize Click Operations

Valid click operations performed by the viewer within the GUI (such as item movement) are now handled by Bukkit's standard functionality. This ensures the exact same processing as Minecraft's normal inventory operations, preventing item disappearance.

Synchronize Changes Later

The modified GUI contents are now copied to the target player's inventory one tick after Bukkit completes the click operation. This completely eliminates processing conflicts and ensures changes are reflected safely.

Control Only Custom Slots

Plugin intervention is now limited solely to clicks on special slots like the trash can or glass panes. These operations cancel the event and are safely handled by the plugin.

This approach—“leave processing to Bukkit and reflect results later”—achieves both stability and a vanilla-like feel, eliminating the item disappearance bug.