Unable to join a multiplayer server - Internal Server Error

[MechanosG]

Heya. Awesome mod. Unfortunately I think something broke. Short version, I'm currently testing a 1.16.4 fabric modpack on a dedicated server without about 5 players currently, containing dankstorage-1.9a-1.16.3.jar, and things were working fine. Then suddenly out of nowhere, I am no longer able to join the server. My client tells me Internal Server Error, and my client console shows absolutely nothing. So I intarweb searched the issue, and the most common reported thing is messed up player data. So I asked the server host to send me the server's playerdata folder, replicated the server locally, then added the playerdata. Sure enough, even in a fresh world, I get the same Internal Server Error. Only, now that I have access to the server, I'm getting this in the server console -

[00:25:15] [Server thread/WARN]: Failed to handle packet for /127.0.0.1:3248
net.minecraft.class_148: Loading entity NBT
	at Not Enough Crashes deobfuscated stack trace.(1.16.4+build.7) ~[?:?]
	at net.minecraft.entity.Entity.fromTag(Entity:1663) ~[?:?]
	at net.minecraft.world.WorldSaveHandler.loadPlayerData(WorldSaveHandler:57) ~[?:?]
	at net.minecraft.server.PlayerManager.loadPlayerData(PlayerManager:344) ~[?:?]
	at net.minecraft.server.PlayerManager.onPlayerConnect(PlayerManager:138) ~[?:?]
	at net.minecraft.server.network.ServerLoginNetworkHandler.acceptPlayer(ServerLoginNetworkHandler:113) ~[?:?]
	at net.minecraft.server.network.ServerLoginNetworkHandler.redirect$bpk000$handlePlayerJoin(ServerLoginNetworkHandler:562) ~[?:?]
	at net.minecraft.server.network.ServerLoginNetworkHandler.tick(ServerLoginNetworkHandler:65) ~[?:?]
	at net.minecraft.network.ClientConnection.tick(ClientConnection:228) ~[?:?]
	at net.minecraft.server.ServerNetworkIo.tick(ServerNetworkIo:173) ~[?:?]
	at net.minecraft.server.MinecraftServer.tickWorlds(MinecraftServer:882) ~[intermediary-server.jar:?]
	at net.minecraft.server.dedicated.MinecraftDedicatedServer.tickWorlds(MinecraftDedicatedServer:312) ~[?:?]
	at net.minecraft.server.MinecraftServer.tick(MinecraftServer:811) ~[intermediary-server.jar:?]
	at net.minecraft.server.MinecraftServer.runServer(MinecraftServer:670) ~[intermediary-server.jar:?]
	at net.minecraft.server.MinecraftServer.method_29739(MinecraftServer:257) ~[intermediary-server.jar:?]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_271]
Caused by: java.lang.NullPointerException
	at Not Enough Crashes deobfuscated stack trace.(1.16.4+build.7) ~[?:?]
	at net.minecraft.item.ItemStack.handler$zmo000$areTagsEqualReturn1(ItemStack:6655) ~[?:?]
	at net.minecraft.item.ItemStack.areTagsEqual(ItemStack:383) ~[?:?]
	at tfar.dankstorage.event.MixinHooks.areItemStacksCompatible(MixinHooks.java:227) ~[dankstorage-1.9a-1.16.3.jar:?]
	at tfar.dankstorage.event.MixinHooks.doesItemStackExist(MixinHooks.java:232) ~[dankstorage-1.9a-1.16.3.jar:?]
	at tfar.dankstorage.event.MixinHooks.voidPickup(MixinHooks.java:150) ~[dankstorage-1.9a-1.16.3.jar:?]
	at tfar.dankstorage.event.MixinHooks.onItemPickup(MixinHooks.java:132) ~[dankstorage-1.9a-1.16.3.jar:?]
	at tfar.dankstorage.event.MixinHooks.interceptItem(MixinHooks.java:47) ~[dankstorage-1.9a-1.16.3.jar:?]
	at net.minecraft.entity.player.PlayerInventory.handler$bdi000$interceptItems(PlayerInventory:2690) ~[?:?]
	at net.minecraft.entity.player.PlayerInventory.insertStack(PlayerInventory) ~[?:?]
	at net.minecraft.entity.player.PlayerEntity.giveItemStack(PlayerEntity:1907) ~[?:?]
	at dev.emi.trinkets.api.PlayerTrinketComponent.fromTag(PlayerTrinketComponent.java:42) ~[trinkets-2.6.7.jar:?]
	at nerdhub.cardinal.components.api.util.container.AbstractComponentContainer.fromTag(AbstractComponentContainer.java:180) ~[f37fc192-c514-48a1-9d3c-a4d8ea68d0c7.jar:?]
	at net.minecraft.entity.Entity.handler$bdp000$fromTag(Entity:8692) ~[?:?]
	at net.minecraft.entity.Entity.fromTag(Entity:1654) ~[?:?]
	... 14 more

I'm not entirely sure, but it appears to be dank storage related. There's no crash, so no crash log. Deleting the playerdata with my UUID allows me to join. I haven't tried to edit the NBT to try and narrow down if it's a specific item in one of my danks, although I'm thinking about it. If you need any extra information, please let me know. I'd give you a mod list, but the pack is up to about 140 mods and I'm not sure how to easily export a list of what mods I'm using without a crashlog.

[Tfarcenim]

throw this on the server and send over the report https://modrinth.com/mod/mixintrace

[MechanosG]

Alright, will do.

[MechanosG]

Does that mod only affect crash reports? Nothing is technically crashing, so no crash report is made. I added mixintrace to both the client and the server, then connected. But the error in console looks identical.

[13:14:38] [Server thread/WARN]: Failed to handle packet for /127.0.0.1:1476
net.minecraft.class_148: Loading entity NBT
	at Not Enough Crashes deobfuscated stack trace.(1.16.4+build.7) ~[?:?]
	at net.minecraft.entity.Entity.fromTag(Entity:1663) ~[?:?]
	at net.minecraft.world.WorldSaveHandler.loadPlayerData(WorldSaveHandler:57) ~[?:?]
	at net.minecraft.server.PlayerManager.loadPlayerData(PlayerManager:344) ~[?:?]
	at net.minecraft.server.PlayerManager.onPlayerConnect(PlayerManager:138) ~[?:?]
	at net.minecraft.server.network.ServerLoginNetworkHandler.acceptPlayer(ServerLoginNetworkHandler:113) ~[?:?]
	at net.minecraft.server.network.ServerLoginNetworkHandler.redirect$bpl000$handlePlayerJoin(ServerLoginNetworkHandler:562) ~[?:?]
	at net.minecraft.server.network.ServerLoginNetworkHandler.tick(ServerLoginNetworkHandler:65) ~[?:?]
	at net.minecraft.network.ClientConnection.tick(ClientConnection:228) ~[?:?]
	at net.minecraft.server.ServerNetworkIo.tick(ServerNetworkIo:173) ~[?:?]
	at net.minecraft.server.MinecraftServer.tickWorlds(MinecraftServer:882) ~[intermediary-server.jar:?]
	at net.minecraft.server.dedicated.MinecraftDedicatedServer.tickWorlds(MinecraftDedicatedServer:312) ~[?:?]
	at net.minecraft.server.MinecraftServer.tick(MinecraftServer:811) ~[intermediary-server.jar:?]
	at net.minecraft.server.MinecraftServer.runServer(MinecraftServer:670) ~[intermediary-server.jar:?]
	at net.minecraft.server.MinecraftServer.method_29739(MinecraftServer:257) ~[intermediary-server.jar:?]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_271]
Caused by: java.lang.NullPointerException
	at Not Enough Crashes deobfuscated stack trace.(1.16.4+build.7) ~[?:?]
	at net.minecraft.item.ItemStack.handler$zmo000$areTagsEqualReturn1(ItemStack:6655) ~[?:?]
	at net.minecraft.item.ItemStack.areTagsEqual(ItemStack:383) ~[?:?]
	at tfar.dankstorage.event.MixinHooks.areItemStacksCompatible(MixinHooks.java:227) ~[dankstorage-1.9a-1.16.3.jar:?]
	at tfar.dankstorage.event.MixinHooks.doesItemStackExist(MixinHooks.java:232) ~[dankstorage-1.9a-1.16.3.jar:?]
	at tfar.dankstorage.event.MixinHooks.voidPickup(MixinHooks.java:150) ~[dankstorage-1.9a-1.16.3.jar:?]
	at tfar.dankstorage.event.MixinHooks.onItemPickup(MixinHooks.java:132) ~[dankstorage-1.9a-1.16.3.jar:?]
	at tfar.dankstorage.event.MixinHooks.interceptItem(MixinHooks.java:47) ~[dankstorage-1.9a-1.16.3.jar:?]
	at net.minecraft.entity.player.PlayerInventory.handler$bdi000$interceptItems(PlayerInventory:2690) ~[?:?]
	at net.minecraft.entity.player.PlayerInventory.insertStack(PlayerInventory) ~[?:?]
	at net.minecraft.entity.player.PlayerEntity.giveItemStack(PlayerEntity:1907) ~[?:?]
	at dev.emi.trinkets.api.PlayerTrinketComponent.fromTag(PlayerTrinketComponent.java:42) ~[trinkets-2.6.7.jar:?]
	at nerdhub.cardinal.components.api.util.container.AbstractComponentContainer.fromTag(AbstractComponentContainer.java:180) ~[d0fe2d0d-1be8-4180-b433-129f936b3e6a.jar:?]
	at net.minecraft.entity.Entity.handler$bdp000$fromTag(Entity:8692) ~[?:?]
	at net.minecraft.entity.Entity.fromTag(Entity:1654) ~[?:?]
	... 14 more

Edit: Tested without not enough crashes just to see if it changed the output at all, but it didn't.

[Tfarcenim]

Damn, didn't realize it wasn't an actual crash, nothing I can do then as I don't know what mod that mixin belongs to

[MechanosG]

Alright, so after a bunch of manual testing.. including manually removing dank storage items from the character one at a time via nbt.. I fixed the problem. I don't think this is actually dank storage related. One of the most recent updates to the modpack, removed the mod Artifacts. Apparently when Artifacts is installed, it enables some Trinket slots and defaults to putting air blocks in them. Then when you remove Artifacts and nothing is enabling those slots, having an air block inside the non-activated slot, blows up everything. Using an nbt editor, I removed the entire trinkets tag, and everything seems to be working again (so far). Sorry for the confusion. I assume this is probably an issue I should report to the Trinkets people.