Paper/nms-patches/RecipeBannerDuplicate.patch

--- a/net/minecraft/server/RecipeBannerDuplicate.java
+++ b/net/minecraft/server/RecipeBannerDuplicate.java
@@ -1,10 +1,12 @@
 package net.minecraft.server;
 
-public class RecipeBannerDuplicate extends IRecipeComplex {
+public class RecipeBannerDuplicate extends ShapelessRecipes { // CraftBukkit - added extends
 
+    // CraftBukkit start - Delegate to new parent class with bogus info
     public RecipeBannerDuplicate(MinecraftKey minecraftkey) {
-        super(minecraftkey);
+        super(minecraftkey, "", new ItemStack(Items.WHITE_BANNER), NonNullList.a(RecipeItemStack.a, RecipeItemStack.a(Items.WHITE_BANNER)));
     }
+    // CraftBukkit end
 
     public boolean a(InventoryCrafting inventorycrafting, World world) {
         EnumColor enumcolor = null;