I do not know what is causing this, but it seems once i reach a ceartain amount of quests it crashed. here is a pastebin.
https://pastebin.com/3n5Z1Rt4

Starting to experience the same issues myself. Been building up a quest book and after making 80 some quests I get this error a lot.

We really need some responses to these issues... these are game breaking.

I dropped all quest mods for 1.12.2
May be the better option here.

I guess I got this to. Got to about 80 quests then "world freeze" and I have to force close the game.

MC 1.12,2
Forge 14.23.2.2654 and 14.23.2.2652 same issue with both.
HQM 1.12.x-5.2.0Alpha1

Is there any timeline on a update?

I just really like this mod and I want to use it.
I really appriciate all the work you modders do.

[14:01:32] [Netty Server IO #1/ERROR] [FML]: There was a critical exception handling a packet on channel hcQuesting
io.netty.handler.codec.EncoderException: java.lang.IllegalArgumentException: The string is too long for this encoding.
at io.netty.handler.codec.MessageToMessageEncoder.write(MessageToMessageEncoder.java:106) ~[MessageToMessageEncoder.class:4.1.9.Final]
at io.netty.handler.codec.MessageToMessageCodec.write(MessageToMessageCodec.java:116) ~[MessageToMessageCodec.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:738) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWriteAndFlush(AbstractChannelHandlerContext.java:801) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:814) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:794) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:831) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.DefaultChannelPipeline.writeAndFlush(DefaultChannelPipeline.java:1032) ~[DefaultChannelPipeline.class:4.1.9.Final]
at io.netty.channel.AbstractChannel.writeAndFlush(AbstractChannel.java:296) ~[AbstractChannel.class:4.1.9.Final]
at net.minecraftforge.fml.common.network.simpleimpl.SimpleNetworkWrapper.sendTo(SimpleNetworkWrapper.java:250) ~[SimpleNetworkWrapper.class:?]
at hardcorequesting.network.NetworkManager.sendToPlayer(NetworkManager.java:47) ~[NetworkManager.class:?]
at hardcorequesting.quests.QuestLine.sendServerSync(QuestLine.java:86) ~[QuestLine.class:?]
at hardcorequesting.event.PlayerTracker.onPlayerLogin(PlayerTracker.java:39) ~[PlayerTracker.class:?]
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_832_PlayerTracker_onPlayerLogin_PlayerLoggedInEvent.invoke(.dynamic) ~[?:?]
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90) ~[ASMEventHandler.class:?]
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:179) ~[EventBus.class:?]
at net.minecraftforge.fml.common.FMLCommonHandler.firePlayerLoggedIn(FMLCommonHandler.java:574) ~[FMLCommonHandler.class:?]
at net.minecraft.server.management.PlayerList.initializeConnectionToPlayer(PlayerList.java:218) ~[pl.class:?]
at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.completeServerSideConnection(NetworkDispatcher.java:256) ~[NetworkDispatcher.class:?]
at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.access$100(NetworkDispatcher.java:72) ~[NetworkDispatcher.class:?]
at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher$1.func_73660_a(NetworkDispatcher.java:205) ~[NetworkDispatcher$1.class:?]
at net.minecraft.network.NetworkManager.func_74428_b(NetworkManager.java:285) ~[gw.class:?]
at net.minecraft.network.NetworkSystem.func_151269_c(NetworkSystem.java:180) ~[oz.class:?]
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:788) ~[MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:666) ~[MinecraftServer.class:?]
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:185) ~[chd.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:524) ~[MinecraftServer.class:?]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_161]
Caused by: java.lang.IllegalArgumentException: The string is too long for this encoding.
at org.apache.commons.lang3.Validate.isTrue(Validate.java:158) ~[commons-lang3-3.5.jar:3.5]
at net.minecraftforge.fml.common.network.ByteBufUtils.writeUTF8String(ByteBufUtils.java:166) ~[ByteBufUtils.class:?]
at hardcorequesting.network.message.PlayerDataSyncMessage.toBytes(PlayerDataSyncMessage.java:53) ~[PlayerDataSyncMessage.class:?]
at net.minecraftforge.fml.common.network.simpleimpl.SimpleIndexedCodec.encodeInto(SimpleIndexedCodec.java:30) ~[SimpleIndexedCodec.class:?]
at net.minecraftforge.fml.common.network.simpleimpl.SimpleIndexedCodec.encodeInto(SimpleIndexedCodec.java:26) ~[SimpleIndexedCodec.class:?]
at net.minecraftforge.fml.common.network.FMLIndexedMessageToMessageCodec.encode(FMLIndexedMessageToMessageCodec.java:71) ~[FMLIndexedMessageToMessageCodec.class:?]
at io.netty.handler.codec.MessageToMessageCodec$1.encode(MessageToMessageCodec.java:67) ~[MessageToMessageCodec$1.class:4.1.9.Final]
at io.netty.handler.codec.MessageToMessageEncoder.write(MessageToMessageEncoder.java:88) ~[MessageToMessageEncoder.class:4.1.9.Final]
... 27 more
[14:01:32] [Netty Server IO #1/ERROR] [FML]: Network Disconnect: A fatal error has occurred, this connection is terminated
[14:01:32] [main/INFO] [journeymap]: Mapping halted in D:\Minecraft\Instances\Basic but fun 1,12,2\journeymap\data\sp\ore testing\DIM0
[14:01:32] [Server thread/INFO] [net.minecraft.network.NetHandlerPlayServer]: Bullorg74 lost connection: A fatal error has occurred, this connection is terminated
[14:01:32] [Server thread/INFO] [net.minecraft.server.MinecraftServer]: Bullorg74 left the game
[14:01:32] [Server thread/INFO] [net.minecraft.network.NetHandlerPlayServer]: Stopping singleplayer server as player logged out
[14:01:32] [Server thread/INFO] [net.minecraft.server.MinecraftServer]: Stopping server
[14:01:32] [Server thread/INFO] [net.minecraft.server.MinecraftServer]: Saving players
[14:01:32] [Server thread/INFO] [net.minecraft.server.MinecraftServer]: Saving worlds
[14:01:32] [Server thread/INFO] [net.minecraft.server.MinecraftServer]: Saving chunks for level 'ore testing'/overworld
[14:01:32] [Server thread/INFO] [FML]: Unloading dimension 0
[14:01:34] [Server thread/INFO] [FML]: Applying holder lookups
[14:01:34] [Server thread/INFO] [FML]: Holder lookups applied

Or if there is anybody clever that can tell me what else I done wrong.

This problem does came from the fact that you're having to many quest, so mc just can't send all of it within the bounds of one packet. This can't b fixed before the rewrite is finished