Server crashes randomly on a player join

`---- Minecraft Crash Report ----
// Daisy, daisy...

Time: 2023-06-30 21:44:38
Description: Exception in server tick loop

java.lang.NullPointerException: Cannot read field "next" because "this.next" is null
at java.base/java.util.LinkedList$ListItr.next(LinkedList.java:897)
at com.fibermc.essentialcommands.playerdata.PlayerDataManager.tick(PlayerDataManager.java:132)
at com.fibermc.essentialcommands.playerdata.PlayerDataManager.lambda$init$0(PlayerDataManager.java:59)
at net.fabricmc.fabric.api.event.lifecycle.v1.ServerTickEvents.lambda$static$2(ServerTickEvents.java:43)
at net.minecraft.server.MinecraftServer.handler$zfj000$fabric-lifecycle-events-v1$onEndTick(MinecraftServer.java:3362)
at net.minecraft.server.MinecraftServer.method_3748(MinecraftServer.java:847)
at net.minecraft.server.MinecraftServer.method_29741(MinecraftServer.java:671)
at net.minecraft.server.MinecraftServer.method_29739(MinecraftServer.java:265)
at java.base/java.lang.Thread.run(Thread.java:833)

A detailed walkthrough of the error, its code path and all known details is as follows:

-- System Details --
Details:
Minecraft Version: 1.20.1
Minecraft Version ID: 1.20.1
Operating System: Linux (amd64) version 5.10.0-21-amd64
Java Version: 17.0.7, Eclipse Adoptium
Java VM Version: OpenJDK 64-Bit Server VM (mixed mode, sharing), Eclipse Adoptium
Memory: 2545320624 bytes (2427 MiB) / 4294967296 bytes (4096 MiB) up to 4294967296 bytes (4096 MiB)
CPUs: 2
Processor Vendor: GenuineIntel
Processor Name: Intel(R) Core(TM) i9-9900K CPU @ 3.60GHz
Identifier: Intel64 Family 6 Model 158 Stepping 13
Microarchitecture: Coffee Lake
Frequency (GHz): 3.60
Number of physical packages: 1
Number of physical CPUs: 8
Number of logical CPUs: 16
Graphics card #0 name: unknown
Graphics card #0 vendor: unknown
Graphics card #0 VRAM (MB): 0.00
Graphics card #0 deviceId: unknown
Graphics card #0 versionInfo: unknown
Virtual memory max (MB): 105296.58
Virtual memory used (MB): 142414.16
Swap memory total (MB): 40927.00
Swap memory used (MB): 22460.33
JVM Flags: 2 total; -Xms128M -Xmx4096M
Fabric Mods:
chunkpregen: Fabric Chunk Pregenerator 0.3.3
colorfulanvils: Colorful Anvils 1.2.0+1.20.x
fabric-api-base: Fabric API Base 0.4.29+b04edc7a77
fabric-permissions-api-v0: fabric-permissions-api 0.2-SNAPSHOT
placeholder-api: Placeholder API 2.1.1+1.20
craterlib: CraterLib 1.0.1
deathlog: DeathLog 0.3.2+1.20
easyauth: Easy Authentication Mod 3.0.0-17
at_favre_lib_bcrypt: bcrypt 0.9.0
at_favre_lib_bytes: bytes 1.5.0
com_mysql_mysql-connector-j: mysql-connector-j 8.0.33
de_mkammerer_argon2-jvm: argon2-jvm 2.11
de_mkammerer_argon2-jvm-nolibs: argon2-jvm-nolibs 2.11
net_java_dev_jna_jna: jna 5.12.1
org_iq80_leveldb_leveldb: leveldb 0.12
org_iq80_leveldb_leveldb-api: leveldb-api 0.12
org_mongodb_bson: bson 4.7.2
org_mongodb_mongodb-driver-core: mongodb-driver-core 4.7.2
org_mongodb_mongodb-driver-sync: mongodb-driver-sync 4.7.2
server_translations_api: Server Translations API 2.0.0+1.20
packet_tweaker: Packet Tweaker 0.4.0+1.19.4
essential_commands: Essential Commands 0.33.2-mc1.20
ec-core: Essential Commands Core 1.3.0-mc1.20
playerabilitylib: Pal 1.8.0
fabric-api: Fabric API 0.84.0+1.20.1
fabric-api-lookup-api-v1: Fabric API Lookup API (v1) 1.6.34+4d8536c977
fabric-biome-api-v1: Fabric Biome API (v1) 13.0.10+b3afc78b77
fabric-block-api-v1: Fabric Block API (v1) 1.0.9+e022e5d177
fabric-command-api-v1: Fabric Command API (v1) 1.2.32+f71b366f77
fabric-command-api-v2: Fabric Command API (v2) 2.2.11+b3afc78b77
fabric-commands-v0: Fabric Commands (v0) 0.2.49+df3654b377
fabric-containers-v0: Fabric Containers (v0) 0.1.61+df3654b377
fabric-content-registries-v0: Fabric Content Registries (v0) 4.0.7+b3afc78b77
fabric-convention-tags-v1: Fabric Convention Tags 1.5.3+b3afc78b77
fabric-crash-report-info-v1: Fabric Crash Report Info (v1) 0.2.18+aeb40ebe77
fabric-data-generation-api-v1: Fabric Data Generation API (v1) 12.1.11+b3afc78b77
fabric-dimensions-v1: Fabric Dimensions API (v1) 2.1.51+b3afc78b77
fabric-entity-events-v1: Fabric Entity Events (v1) 1.5.21+b3afc78b77
fabric-events-interaction-v0: Fabric Events Interaction (v0) 0.6.0+b3afc78b77
fabric-events-lifecycle-v0: Fabric Events Lifecycle (v0) 0.2.61+df3654b377
fabric-game-rule-api-v1: Fabric Game Rule API (v1) 1.0.38+b04edc7a77
fabric-item-api-v1: Fabric Item API (v1) 2.1.26+b3afc78b77
fabric-item-group-api-v1: Fabric Item Group API (v1) 4.0.7+b3afc78b77
fabric-lifecycle-events-v1: Fabric Lifecycle Events (v1) 2.2.20+b3afc78b77
fabric-loot-api-v2: Fabric Loot API (v2) 1.1.37+b3afc78b77
fabric-loot-tables-v1: Fabric Loot Tables (v1) 1.1.41+9e7660c677
fabric-message-api-v1: Fabric Message API (v1) 5.1.6+b3afc78b77
fabric-mining-level-api-v1: Fabric Mining Level API (v1) 2.1.47+b3afc78b77
fabric-networking-api-v1: Fabric Networking API (v1) 1.3.8+b3afc78b77
fabric-networking-v0: Fabric Networking (v0) 0.3.48+df3654b377
fabric-object-builder-api-v1: Fabric Object Builder API (v1) 11.0.6+b3afc78b77
fabric-particles-v1: Fabric Particles (v1) 1.0.28+b3afc78b77
fabric-recipe-api-v1: Fabric Recipe API (v1) 1.0.18+b3afc78b77
fabric-registry-sync-v0: Fabric Registry Sync (v0) 2.2.6+b3afc78b77
fabric-rendering-data-attachment-v1: Fabric Rendering Data Attachment (v1) 0.3.33+b3afc78b77
fabric-rendering-fluids-v1: Fabric Rendering Fluids (v1) 3.0.26+b3afc78b77
fabric-resource-conditions-api-v1: Fabric Resource Conditions API (v1) 2.3.5+ea08f9d877
fabric-resource-loader-v0: Fabric Resource Loader (v0) 0.11.7+f7923f6d77
fabric-screen-handler-api-v1: Fabric Screen Handler API (v1) 1.3.27+b3afc78b77
fabric-transfer-api-v1: Fabric Transfer API (v1) 3.2.2+b3afc78b77
fabric-transitive-access-wideners-v1: Fabric Transitive Access Wideners (v1) 4.2.0+b3afc78b77
fabric-language-kotlin: Fabric Language Kotlin 1.9.6+kotlin.1.8.22
org_jetbrains_kotlin_kotlin-reflect: kotlin-reflect 1.8.22
org_jetbrains_kotlin_kotlin-stdlib: kotlin-stdlib 1.8.22
org_jetbrains_kotlin_kotlin-stdlib-jdk7: kotlin-stdlib-jdk7 1.8.22
org_jetbrains_kotlin_kotlin-stdlib-jdk8: kotlin-stdlib-jdk8 1.8.22
org_jetbrains_kotlinx_atomicfu-jvm: atomicfu-jvm 0.21.0
org_jetbrains_kotlinx_kotlinx-coroutines-core-jvm: kotlinx-coroutines-core-jvm 1.7.1
org_jetbrains_kotlinx_kotlinx-coroutines-jdk8: kotlinx-coroutines-jdk8 1.7.1
org_jetbrains_kotlinx_kotlinx-datetime-jvm: kotlinx-datetime-jvm 0.4.0
org_jetbrains_kotlinx_kotlinx-serialization-cbor-jvm: kotlinx-serialization-cbor-jvm 1.5.1
org_jetbrains_kotlinx_kotlinx-serialization-core-jvm: kotlinx-serialization-core-jvm 1.5.1
org_jetbrains_kotlinx_kotlinx-serialization-json-jvm: kotlinx-serialization-json-jvm 1.5.1
fabricloader: Fabric Loader 0.14.21
fabrictailor: Fabric Tailor 2.1.2
config2brigadier: Config to Brigadier 1.2.3
ferritecore: FerriteCore 6.0.0
goml: Get Off My Lawn ReServed 1.9.0+1.20-rc1
cardinal-components-base: Cardinal Components API (base) 5.0.2
cardinal-components-world: Cardinal Components API (worlds) 5.0.2
polymer-core: Polymer (Core) 0.5.0-rc.2+1.20-rc1
polymer-networking: Polymer (Networking) 0.5.0-rc.2+1.20-rc1
polymer-common: Polymer (Common) 0.5.0-rc.2+1.20-rc1
rtree-3i-lite-fabric: rtree-3i-lite for Fabric 0.3.0
sgui: sgui 1.2.2+1.20
horsebuff: HorseBuff 2.1.1
cloth-config: Cloth Config v11 11.0.99
cloth-basic-math: cloth-basic-math 0.6.1
htm: Hey That's Mine 1.1.9
common-protection-api: Common Protection API 1.0.0
inventorysorter: Inventory Sorter 1.9.0-1.20
kyrptconfig: Kyrpt Config 1.5.6-1.20
itemflexer: ItemFlexer 1.3.0
microconfig: Microconfig 2.2.1
java: OpenJDK 64-Bit Server VM 17
keepheadnames: Keep Head Names 1.5.1
krypton: Krypton 0.2.3
com_velocitypowered_velocity-native: velocity-native 3.2.0-SNAPSHOT
ledger: Ledger 1.2.8
lithium: Lithium 0.11.2
mclogs: Mclogs 1.4.1
gs_mclo_api: api 4.0.1
memoryleakfix: Memory Leak Fix 1.1.1
com_github_llamalad7_mixinextras: MixinExtras 0.2.0-beta.8
minecraft: Minecraft 1.20.1
mixintrace: MixinTrace 1.1.1+1.17
mods-command: Mods Command 1.1.3
adventure-platform-fabric: adventure-platform-fabric 5.10.0-SNAPSHOT
net_kyori_adventure-api: adventure-api 4.14.0
net_kyori_adventure-key: adventure-key 4.14.0
net_kyori_adventure-platform-api: adventure-platform-api 4.3.0
net_kyori_adventure-text-logger-slf4j: adventure-text-logger-slf4j 4.14.0
net_kyori_adventure-text-minimessage: adventure-text-minimessage 4.14.0
net_kyori_adventure-text-serializer-ansi: adventure-text-serializer-ansi 4.14.0
net_kyori_adventure-text-serializer-gson: adventure-text-serializer-gson 4.14.0
net_kyori_adventure-text-serializer-json: adventure-text-serializer-json 4.14.0
net_kyori_adventure-text-serializer-plain: adventure-text-serializer-plain 4.14.0
net_kyori_ansi: ansi 1.0.0
net_kyori_examination-api: examination-api 1.3.0
net_kyori_examination-string: examination-string 1.3.0
cloud: Cloud 1.8.3
cloud_commandframework_cloud-brigadier_: cloud-brigadier 1.8.3
cloud_commandframework_cloud-core_: cloud-core 1.8.3
cloud_commandframework_cloud-services_: cloud-services 1.8.3
cloud_commandframework_cloud-minecraft-extras: cloud-minecraft-extras 1.8.3
com_typesafe_config: config 1.4.2
io_leangen_geantyref_geantyref: geantyref 1.3.13
org_spongepowered_configurate-core: configurate-core 4.1.2
org_spongepowered_configurate-hocon: configurate-hocon 4.1.2
org_spongepowered_configurate-yaml: configurate-yaml 4.1.2
org_yaml_snakeyaml: snakeyaml 1.34-SNAPSHOT
multiworldborders: Multi World Borders 1.6.1-fabric-1.20
nochatreports: No Chat Reports 1.20.1-v2.2.2
owo: oωo 0.11.0+1.20
blue_endless_jankson: jankson 1.2.2
pingspam: Pingspam 1.3.1+1.20
onedatastore: One Data Store 0.1.3+1.20
plan: Plan 5.5 build 2411
sdlink: Simple Discord Link 2.2.2
spark: spark 1.10.42
starlight: Starlight 1.1.2+fabric.dbc156f
styledchat: Styled Chat 2.2.0+1.20
styledplayerlist: Styled Player List 3.1.1+1.20.1
player-data-api: Player Data API 0.2.2+1.19.3
predicate-api: Predicate API 0.1.2+1.20
tabtps-fabric: TabTPS 1.3.18
net_kyori_adventure-serializer-configurate4: adventure-serializer-configurate4 4.14.0
net_kyori_adventure-text-feature-pagination: adventure-text-feature-pagination 4.0.0-SNAPSHOT
net_kyori_adventure-text-serializer-legacy: adventure-text-serializer-legacy 4.14.0
textile_backup: Textile Backup 3.1.0-1.20
com_github_shevek_parallelgzip: parallelgzip af5f5c297e735f3f2df7aa4eb0e19a5810b8aff6
org_apache_commons_commons-compress: commons-compress 1.22
org_tukaani_xz: xz 1.9
vcinteraction: Voice Chat Interaction 1.20.1-1.0.3
polymer-registry-sync-manipulator: Polymer (Registry Sync Manipulator) 0.5.0+1.20
voicechat: Simple Voice Chat 1.20.1-2.4.12
Server Running: true
Player Count: 4 / 20; [class_3222['Stonebanks16'/192726, l='ServerLevel[world]', x=-318.28, y=65.00, z=236.96], class_3222['S_Sam312'/199849, l='ServerLevel[world]', x=8.06, y=73.00, z=331.28], class_3222['SirePoopAlot'/211602, l='ServerLevel[world]', x=-57.31, y=71.00, z=120.95], class_3222['iglushrek'/212339, l='ServerLevel[world]', x=194.96, y=76.54, z=814.95]]
Data Packs: vanilla, fabric, file/afk display v1.1.4 (MC 1.20.x).zip, file/anti enderman grief v1.1.4 (MC 1.20.x).zip, file/armor statues v2.8.5 (MC 1.20.x).zip, file/double shulker shells v1.3.4 (MC 1.20.x).zip, file/more mob heads v2.12.1 (MC 1.20.x).zip, file/player head drops v1.1.4 (MC 1.20.x).zip, file/silence mobs v1.1.4 (MC 1.20.x).zip, file/track raw statistics v1.7.0 (MC 1.20.x).zip, file/track statistics v1.1.5 (MC 1.20.x).zip, file/unlock all recipes v2.0.5 (MC 1.20.x).zip, file/wandering trades hermit edition v1.8.1 (MC 1.20.x).zip, file/BlazeandCave's+Advancements+Pack+1.16.1.zip, file/fast leaf decay v2.0.7 (MC 1.20.x).zip
Enabled Feature Flags: minecraft:vanilla
World Generation: Stable
Is Modded: Definitely; Server brand changed to 'fabric'
Type: Dedicated Server (map_server.txt)`

I'm not entirely sure how this is happening, but I just simplified this code path a tiny bit. Hoping that resolves the issue (264e86f). Will be included in the next patch release.

I'm not entirely sure how this is happening, but I just simplified this code path a tiny bit. Hoping that resolves the issue (264e86f). Will be included in the next patch release.

Hey, thank you! should I download the build file or wait for release?

Downloading the build from the GH Action artifacts should be good. Not sure when next release will be yet.

Hey, your update fixed it! thanks!