Create Dupe Patch

Create Dupe Patch

A lightweight, server-side fix for the Create mod duplication exploit that allows Schematicannons to duplicate items with NBT data (such as placards, framed blocks, and other items with inventory/data).

What it does:

• Patches Create issue #9511 where Schematicannons could print items with full NBT while only consuming the base block
• Ensures the material checklist correctly accounts for items inside block entities
• Prevents item duplication through schematic printing

Key Features:

• ✅ Server-side only – No client installation required
• ✅ Backport for 1.20.1 – Brings the 1.21 fix to 1.20.1 modpacks
• ✅ Lightweight – Single mixin, minimal performance impact
• ✅ Compatible – Works with existing Create installations without breaking functionality

Why this matters:
The vanilla Create mod in 1.20.1 has a critical bug where schematics containing blocks with items (placards, storage blocks, etc.) can be printed while only consuming the empty block, effectively duplicating valuable items. This exploit was fixed upstream in Create 6.0.9+ for 1.21, but this patch brings that fix to 1.20.1 servers.