MinecraftComponentSerializer throws UnsupportedOperationException

[LoneDev6]

Tested on:

• 1.19.4
• 1.20.2
• 1.20.4

I get UnsupportedOperationException when calling MinecraftComponentSerializer.get().serialize(component); on villagers names trade GUI name and some other texts.

Only way to fix that is to convert the adventure Component to Json String and use NMS to convert the Json String to Minecraft MutableComponent, I tried that and works fine.
Seems the issue is somehow caused by the json tree -> MutableComponent implementation.

        <dependency>
            <groupId>net.kyori</groupId>
            <artifactId>adventure-api</artifactId>
            <version>4.15.0</version>
        </dependency>
        <dependency>
            <groupId>net.kyori</groupId>
            <artifactId>adventure-text-serializer-gson</artifactId>
            <version>4.15.0</version>
        </dependency>
        <dependency>
            <groupId>net.kyori</groupId>
            <artifactId>adventure-text-serializer-gson-legacy-impl</artifactId>
            <version>4.15.0</version>
        </dependency>
        <dependency>
            <groupId>net.kyori</groupId>
            <artifactId>adventure-platform-bukkit</artifactId>
            <version>4.3.2</version>
        </dependency>
        <dependency>
            <groupId>net.kyori</groupId>
            <artifactId>adventure-text-minimessage</artifactId>
            <version>4.15.0</version>
        </dependency>

[15:02:10 ERROR]: [ItemsAdder] Unhandled exception occurred in onPacketSending(PacketEvent) for ItemsAdder
java.lang.UnsupportedOperationException: com.google.gson.JsonSyntaxException: Expected id to be a string, was an array ([140...38])
	at net.kyori.adventure.platform.bukkit.MinecraftComponentSerializer.serialize(MinecraftComponentSerializer.java:225) ~[LoneLibs.jar:?]
	at ia.m.iI.a(SourceFile:97) ~[ItemsAdder_3.6.3-beta-5.jar:?]
	at ia.m.hy.onPacketSending(SourceFile:173) ~[ItemsAdder_3.6.3-beta-5.jar:?]
	at com.comphenix.protocol.injector.SortedPacketListenerList.invokeSendingListener(SortedPacketListenerList.java:219) ~[ProtocolLib.jar:?]
	at com.comphenix.protocol.injector.SortedPacketListenerList.invokeUnpackedPacketSending(SortedPacketListenerList.java:204) ~[ProtocolLib.jar:?]
	at com.comphenix.protocol.injector.SortedPacketListenerList.invokePacketSending(SortedPacketListenerList.java:149) ~[ProtocolLib.jar:?]
	at com.comphenix.protocol.injector.SortedPacketListenerList.invokePacketSending(SortedPacketListenerList.java:139) ~[ProtocolLib.jar:?]
	at com.comphenix.protocol.injector.PacketFilterManager.postPacketToListeners(PacketFilterManager.java:553) ~[ProtocolLib.jar:?]
	at com.comphenix.protocol.injector.PacketFilterManager.invokePacketSending(PacketFilterManager.java:526) ~[ProtocolLib.jar:?]
	at com.comphenix.protocol.injector.netty.manager.NetworkManagerInjector.onPacketSending(NetworkManagerInjector.java:100) ~[ProtocolLib.jar:?]
	at com.comphenix.protocol.injector.netty.channel.NettyChannelInjector.processOutbound(NettyChannelInjector.java:553) ~[ProtocolLib.jar:?]
	at com.comphenix.protocol.injector.netty.channel.NettyChannelInjector$2.doProxyRunnable(NettyChannelInjector.java:456) ~[ProtocolLib.jar:?]
	at com.comphenix.protocol.injector.netty.channel.NettyEventLoopProxy.proxyRunnable(NettyEventLoopProxy.java:43) ~[ProtocolLib.jar:?]
	at com.comphenix.protocol.injector.netty.channel.NettyEventLoopProxy.execute(NettyEventLoopProxy.java:252) ~[ProtocolLib.jar:?]
	at net.minecraft.network.Connection.sendPacket(Connection.java:432) ~[?:?]
	at net.minecraft.network.Connection.send(Connection.java:392) ~[?:?]
	at net.minecraft.server.network.ServerCommonPacketListenerImpl.send(ServerCommonPacketListenerImpl.java:276) ~[purpur-1.20.2.jar:git-Purpur-2095]
	at net.minecraft.server.network.ServerCommonPacketListenerImpl.send(ServerCommonPacketListenerImpl.java:261) ~[purpur-1.20.2.jar:git-Purpur-2095]
	at net.minecraft.server.level.ServerPlayer.openMenu(ServerPlayer.java:1640) ~[?:?]
	at net.minecraft.world.item.trading.Merchant.openTradingScreen(Merchant.java:41) ~[?:?]
	at net.minecraft.world.entity.npc.Villager.startTrading(Villager.java:453) ~[?:?]
	at net.minecraft.world.entity.npc.Villager.mobInteract(Villager.java:431) ~[?:?]
	at net.minecraft.world.entity.Mob.interact(Mob.java:1374) ~[?:?]
	at net.minecraft.world.entity.player.Player.interactOn(Player.java:1174) ~[?:?]
	at net.minecraft.server.network.ServerGamePacketListenerImpl$4.performInteraction(ServerGamePacketListenerImpl.java:2816) ~[?:?]
	at net.minecraft.server.network.ServerGamePacketListenerImpl$4.a(ServerGamePacketListenerImpl.java:2836) ~[?:?]
	at net.minecraft.network.protocol.game.ServerboundInteractPacket$InteractionAction.dispatch(ServerboundInteractPacket.java:131) ~[?:?]
	at net.minecraft.network.protocol.game.ServerboundInteractPacket.dispatch(ServerboundInteractPacket.java:80) ~[?:?]
	at net.minecraft.server.network.ServerGamePacketListenerImpl.handleInteract(ServerGamePacketListenerImpl.java:2775) ~[?:?]
	at net.minecraft.network.protocol.game.ServerboundInteractPacket.handle(ServerboundInteractPacket.java:67) ~[?:?]
	at net.minecraft.network.protocol.game.ServerboundInteractPacket.handle(ServerboundInteractPacket.java:12) ~[?:?]
	at net.minecraft.network.protocol.PacketUtils.lambda$ensureRunningOnSameThread$0(PacketUtils.java:53) ~[?:?]
	at net.minecraft.server.TickTask.run(TickTask.java:18) ~[purpur-1.20.2.jar:git-Purpur-2095]
	at net.minecraft.util.thread.BlockableEventLoop.doRunTask(BlockableEventLoop.java:153) ~[?:?]
	at net.minecraft.util.thread.ReentrantBlockableEventLoop.doRunTask(ReentrantBlockableEventLoop.java:24) ~[?:?]
	at net.minecraft.server.MinecraftServer.doRunTask(MinecraftServer.java:1351) ~[purpur-1.20.2.jar:git-Purpur-2095]
	at net.minecraft.server.MinecraftServer.d(MinecraftServer.java:193) ~[purpur-1.20.2.jar:git-Purpur-2095]
	at net.minecraft.util.thread.BlockableEventLoop.pollTask(BlockableEventLoop.java:126) ~[?:?]
	at net.minecraft.server.MinecraftServer.pollTaskInternal(MinecraftServer.java:1328) ~[purpur-1.20.2.jar:git-Purpur-2095]
	at net.minecraft.server.MinecraftServer.pollTask(MinecraftServer.java:1321) ~[purpur-1.20.2.jar:git-Purpur-2095]
	at net.minecraft.util.thread.BlockableEventLoop.managedBlock(BlockableEventLoop.java:136) ~[?:?]
	at net.minecraft.server.MinecraftServer.waitUntilNextTick(MinecraftServer.java:1299) ~[purpur-1.20.2.jar:git-Purpur-2095]
	at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1187) ~[purpur-1.20.2.jar:git-Purpur-2095]
	at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:320) ~[purpur-1.20.2.jar:git-Purpur-2095]
	at java.lang.Thread.run(Thread.java:833) ~[?:?]
Caused by: com.google.gson.JsonSyntaxException: Expected id to be a string, was an array ([140...38])
	at net.minecraft.util.GsonHelper.convertToString(GsonHelper.java:97) ~[?:?]
	at net.minecraft.util.GsonHelper.getAsString(GsonHelper.java:103) ~[?:?]
	at net.minecraft.network.chat.HoverEvent$EntityTooltipInfo.create(HoverEvent.java:177) ~[?:?]
	at net.minecraft.network.chat.HoverEvent$Action.deserialize(HoverEvent.java:136) ~[?:?]
	at net.minecraft.network.chat.HoverEvent.deserialize(HoverEvent.java:80) ~[?:?]
	at net.minecraft.network.chat.Style$Serializer.getHoverEvent(Style.java:405) ~[?:?]
	at net.minecraft.network.chat.Style$Serializer.deserialize(Style.java:377) ~[?:?]
	at net.minecraft.network.chat.Style$Serializer.deserialize(Style.java:364) ~[?:?]
	at com.google.gson.internal.bind.TreeTypeAdapter.read(TreeTypeAdapter.java:76) ~[gson-2.10.1.jar:?]
	at com.google.gson.Gson.fromJson(Gson.java:1227) ~[gson-2.10.1.jar:?]
	at com.google.gson.Gson.fromJson(Gson.java:1329) ~[gson-2.10.1.jar:?]
	at com.google.gson.Gson.fromJson(Gson.java:1300) ~[gson-2.10.1.jar:?]
	at com.google.gson.internal.bind.TreeTypeAdapter$GsonContextImpl.deserialize(TreeTypeAdapter.java:179) ~[gson-2.10.1.jar:?]
	at net.minecraft.network.chat.Component$Serializer.deserialize(Component.java:361) ~[?:?]
	at net.minecraft.network.chat.Component$Serializer.deserialize(Component.java:222) ~[?:?]
	at com.google.gson.internal.bind.TreeTypeAdapter.read(TreeTypeAdapter.java:76) ~[gson-2.10.1.jar:?]
	at com.google.gson.Gson.fromJson(Gson.java:1227) ~[gson-2.10.1.jar:?]
	at com.google.gson.Gson.fromJson(Gson.java:1329) ~[gson-2.10.1.jar:?]
	at com.google.gson.Gson.fromJson(Gson.java:1271) ~[gson-2.10.1.jar:?]
	at net.minecraft.network.chat.Component$Serializer.fromJson(Component.java:536) ~[?:?]
	at net.kyori.adventure.platform.bukkit.MinecraftComponentSerializer.serialize(MinecraftComponentSerializer.java:221) ~[LoneLibs.jar:?]
	... 44 more
[15:02:10 ERROR]: Parameters: 
  net.minecraft.network.protocol.game.PacketPlayOutOpenWindow@2d1a960d[
    a=11
    b=net.minecraft.world.inventory.Containers@3a73661d
    c=translation{key='entity.minecraft.villager.farmer', args=[]}[style={hoverEvent=HoverEvent{action=<action show_entity>, value='net.minecraft.network.chat.ChatHoverable$b@8abdf856'},insertion=08629de5-8c47-4554-8ad5-1f075a194266}]
  ]

[Machine-Maker]

For clarification, this also happens on 1.19.4 and 1.20.4? The stacktrace you provided is from 1.20.2 which is neither of those versions.

[LoneDev6]

This error was taken from a customer report, so you can also add 1.20.2 to the list of versions with the issue.

Here is the json:

{
  "insertion": "d9808418-fea1-480a-ba86-d6081693d626",
  "hoverEvent": {
    "action": "show_entity",
    "contents": {
      "type": "minecraft:villager",
      "id": [-645889000, -22984694, -1165568504, 378787366],
      "name": { "translate": "entity.minecraft.villager.farmer" }
    }
  },
  "translate": "entity.minecraft.villager.farmer"
}

It has to do with the fact that uuid (id) is a string in recent versions of the game and not an array, it seems.

---

Here is some information on what needs to be changed to fix that issue:
KyoriPowered/adventure#1015

The fix:
WiIIiam278/Velocity@dec36bd#diff-2856d6b2f881f52815f9efe35d7d3dd11a2e813ddd332cda3ecb7cd560a8821b