diff --git a/patches/server/1038-Fix-UnsafeValues-loadAdvancement.patch b/patches/server/1038-Fix-UnsafeValues-loadAdvancement.patch
new file mode 100644
index 0000000000..985e11cac5
--- /dev/null
+++ b/patches/server/1038-Fix-UnsafeValues-loadAdvancement.patch
@@ -0,0 +1,29 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: LemonCaramel <admin@caramel.moe>
+Date: Sun, 24 Sep 2023 20:19:44 +0900
+Subject: [PATCH] Fix UnsafeValues#loadAdvancement
+
+
+diff --git a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
+index 96f6e0554baf5915dd1f5b93f3bcfe7a13393c29..806fb1064a1769d1251f2a2b04372275754d2aeb 100644
+--- a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
++++ b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
+@@ -314,7 +314,17 @@ public final class CraftMagicNumbers implements UnsafeValues {
+         JsonObject jsonobject = GsonHelper.convertToJsonObject(jsonelement, "advancement");
+         net.minecraft.advancements.Advancement nms = net.minecraft.advancements.Advancement.fromJson(jsonobject, new DeserializationContext(minecraftkey, MinecraftServer.getServer().getLootData()));
+         if (nms != null) {
+-            MinecraftServer.getServer().getAdvancements().advancements.put(minecraftkey, new AdvancementHolder(minecraftkey, nms));
++            // Paper start - Fix throw UnsupportedOperationException
++            //MinecraftServer.getServer().getAdvancements().advancements.put(minecraftkey, new AdvancementHolder(minecraftkey, nms));
++            final com.google.common.collect.ImmutableMap.Builder<ResourceLocation, AdvancementHolder> mapBuilder = com.google.common.collect.ImmutableMap.builder();
++            mapBuilder.putAll(MinecraftServer.getServer().getAdvancements().advancements);
++
++            final AdvancementHolder holder = new AdvancementHolder(minecraftkey, nms);
++            mapBuilder.put(minecraftkey, holder);
++
++            MinecraftServer.getServer().getAdvancements().advancements = mapBuilder.build();
++            MinecraftServer.getServer().getAdvancements().tree().addAll(List.of(holder));
++            // Paper end - Fix throw UnsupportedOperationException
+             Advancement bukkit = Bukkit.getAdvancement(key);
+ 
+             if (bukkit != null) {