NbtAccounterException: Tried to read NBT tag with too high complexity, depth > 512

Stack trace

https://mclo.gs/GZirUfn

Plugin and Datapack List

Paper Plugins (9): CraftBook5, HuskHomes, LiteEco, MiniCmd, MiniGuard, MiniLog, SignRewards, VaultChatFormatter, VillagerLobotimizer
Bukkit Plugins (34): Bolt, BoltWorldGuard, ChunkSpawnerLimiter, Chunky, ChunkyBorder, ColoredSigns, DiscordSRV, dynmap, EntityDetection, FlyingCarpet, ImageFrame, LogBlock, LogBlockQuestioner, LuckPerms, mcMMO, Multiverse-Core, Multiverse-Portals, OpenInv, packetevents, PremiumVanish, ProtocolLib, QuickShop-Hikari, RedstoneClockDetector, SafariNet, ServerLinksZ, UnifiedMetrics, Vault, ViaVersion, VoidGen, Votifier, Vulcan, WorldEdit, WorldGuard, ZHorse

[Fri 23:22:47 INFO Server] There are 6 data pack(s) enabled: [vanilla (built-in)], [file/bukkit (world)], [file/invisibleitemframe (world)], [file/sit (world)], [file/minicraft (world)], [paper (built-in)]
[Fri 23:22:47 INFO Server] There are no more data packs available

Actions to reproduce (if known)

On 11. Feb 2026 I noticed first a chunk reset on my server spawn. I did recover it from an backup and it did work for a few weeks. In the past Weeks the chunk doesnt hold any longer. Its get resetted almost every day.

The chunk does hold 3 chests. Two with 3 books each containing 43 pages about our server (first steps, warps, guidelines) full of NBT data. And one chest with 3 maps containing qr codes built block by block in a flat world.

Paper version

1.21.11-130-ver/1.21.11@c5a2736 (2026-04-11T11:14:19Z) (Implementing API version 1.21.11-R0.1-SNAPSHOT)

Other

No response

Start with the linked stack trace and the Paper 1.21.11 version, then reproduce using the described chunk containing books and maps with extensive NBT data. Trace which NBT data triggers the depth limit and determine whether the resulting exception causes the chunk reset; done means the failure is isolated and a verified fix or mitigation is identified.