ZNPCsPlus player head hologram breaks interaction with NPC's

[Tuchan]

After I installed the Quests plugin, whenever I clicked on an NPC with a player head in its hologram, I received this error message:

[ERROR]: Could not pass event NpcInteractEvent to Quests v3.15-f7de2dc
java.lang.IllegalStateException: Failed to convert NBT to JSON.

Full error message

[15:14:30 ERROR]: Could not pass event NpcInteractEvent to Quests v3.15-f7de2dc
java.lang.IllegalStateException: Failed to convert NBT to JSON.
	at lol.pyr.znpcsplus.libraries.packetevents.api.protocol.nbt.codec.NBTCodec.nbtToJson(NBTCodec.java:145) ~[ZNPCsPlus-2.0.0-SNAPSHOT.jar:?]
	at lol.pyr.znpcsplus.libraries.packetevents.api.protocol.nbt.codec.NBTCodec.nbtToJson(NBTCodec.java:139) ~[ZNPCsPlus-2.0.0-SNAPSHOT.jar:?]
	at lol.pyr.znpcsplus.libraries.packetevents.api.protocol.nbt.codec.NBTCodec.nbtToJson(NBTCodec.java:139) ~[ZNPCsPlus-2.0.0-SNAPSHOT.jar:?]
	at lol.pyr.znpcsplus.hologram.HologramItem.serialize(HologramItem.java:109) ~[ZNPCsPlus-2.0.0-SNAPSHOT.jar:?]
	at lol.pyr.znpcsplus.hologram.HologramImpl.getLine(HologramImpl.java:80) ~[ZNPCsPlus-2.0.0-SNAPSHOT.jar:?]
	at com.leonardobishop.quests.bukkit.tasktype.type.dependent.ZNPCsPlusDeliverTaskType.onNpcInteract(ZNPCsPlusDeliverTaskType.java:36) ~[Quests-3.15-f7de2dc.jar:?]
	at com.destroystokyo.paper.event.executor.asm.generated.GeneratedEventExecutor116.execute(Unknown Source) ~[?:?]
	at org.bukkit.plugin.EventExecutor$2.execute(EventExecutor.java:77) ~[paper-api-1.20.2-R0.1-SNAPSHOT.jar:?]
	at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:77) ~[paper-api-1.20.2-R0.1-SNAPSHOT.jar:git-Paper-318]
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[paper-api-1.20.2-R0.1-SNAPSHOT.jar:?]
	at io.papermc.paper.plugin.manager.PaperEventManager.callEvent(PaperEventManager.java:54) ~[paper-1.20.2.jar:git-Paper-318]
	at io.papermc.paper.plugin.manager.PaperPluginManagerImpl.callEvent(PaperPluginManagerImpl.java:126) ~[paper-1.20.2.jar:git-Paper-318]
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:615) ~[paper-api-1.20.2-R0.1-SNAPSHOT.jar:?]
	at lol.pyr.znpcsplus.interaction.InteractionPacketListener.onPacketReceive(InteractionPacketListener.java:46) ~[ZNPCsPlus-2.0.0-SNAPSHOT.jar:?]
	at lol.pyr.znpcsplus.libraries.packetevents.api.event.PacketListener$1.onPacketReceive(PacketListener.java:41) ~[ZNPCsPlus-2.0.0-SNAPSHOT.jar:?]
	at lol.pyr.znpcsplus.libraries.packetevents.api.event.PacketReceiveEvent.call(PacketReceiveEvent.java:45) ~[ZNPCsPlus-2.0.0-SNAPSHOT.jar:?]
	at lol.pyr.znpcsplus.libraries.packetevents.api.event.EventManager.callEvent(EventManager.java:52) ~[ZNPCsPlus-2.0.0-SNAPSHOT.jar:?]
	at lol.pyr.znpcsplus.libraries.packetevents.api.util.PacketEventsImplHelper.handleServerBoundPacket(PacketEventsImplHelper.java:82) ~[ZNPCsPlus-2.0.0-SNAPSHOT.jar:?]
	at lol.pyr.znpcsplus.libraries.packetevents.impl.injector.handlers.PacketEventsDecoder.read(PacketEventsDecoder.java:51) ~[ZNPCsPlus-2.0.0-SNAPSHOT.jar:?]
	at lol.pyr.znpcsplus.libraries.packetevents.impl.injector.handlers.PacketEventsDecoder.decode(PacketEventsDecoder.java:58) ~[ZNPCsPlus-2.0.0-SNAPSHOT.jar:?]
	at lol.pyr.znpcsplus.libraries.packetevents.impl.injector.handlers.PacketEventsDecoder.decode(PacketEventsDecoder.java:35) ~[ZNPCsPlus-2.0.0-SNAPSHOT.jar:?]
	at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:88) ~[netty-codec-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:346) ~[netty-codec-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:318) ~[netty-codec-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:346) ~[netty-codec-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:333) ~[netty-codec-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:454) ~[netty-codec-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:290) ~[netty-codec-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103) ~[netty-codec-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:286) ~[netty-handler-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:442) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.handler.flush.FlushConsolidationHandler.channelRead(FlushConsolidationHandler.java:152) ~[netty-handler-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:442) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:440) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:788) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:724) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:650) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562) ~[netty-transport-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997) ~[netty-common-4.1.97.Final.jar:4.1.97.Final]
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.97.Final.jar:4.1.97.Final]

After reporting this issue to the Quests team, it seems ZNPCsPlus fails while trying to serialize the hologram.

Steps to Reproduce (with Quests installed)

• Install the newest version of ZNPCSPlus and Quests
• Create an NPC with a simple action (ex: /npc action add message <id> ANY_CLICK 1 0 test)
• Add a player head item hologram (ex: /npc holo insteritem <id> 0 while holding the player head)
• Click on the NPC, it should now display an error in the console)