Crash when using a brush

Server Implementation

Paper

Server Version

1.21.11

Describe the bug

Server crash when rapidly using a brush
//br smooth 5 5

To Reproduce

1. //br smooth 5 5
2. Click fast or use fastuse on meteor
3. crash after a while

Expected behaviour

Um

Screenshots / Videos

No response

Error log (if applicable)

[21:02:09 INFO]: Using com.sk89q.worldedit.bukkit.adapter.impl.fawe.v1_21_11.PaperweightStarlightRelighterFactory as relighter factory.
[21:02:09 INFO]: <yagoat_real> ik
[21:02:09 ERROR]: Encountered an unexpected exception
net.minecraft.ReportedException: Exception ticking world
at net.minecraft.server.MinecraftServer.tickChildren(MinecraftServer.java:1860) ~[purpur-1.21.11.jar:1.21.11-2566-0fbf8d2]
at net.minecraft.server.MinecraftServer.tickServer(MinecraftServer.java:1647) ~[purpur-1.21.11.jar:1.21.11-2566-0fbf8d2]
at net.minecraft.server.dedicated.DedicatedServer.tickServer(DedicatedServer.java:473) ~[purpur-1.21.11.jar:1.21.11-2566-0fbf8d2]
at net.minecraft.server.MinecraftServer.processPacketsAndTick(MinecraftServer.java:1703) ~[purpur-1.21.11.jar:1.21.11-2566-0fbf8d2]
at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1371) ~[purpur-1.21.11.jar:1.21.11-2566-0fbf8d2]
at net.minecraft.server.MinecraftServer.lambda$spin$2(MinecraftServer.java:392) ~[purpur-1.21.11.jar:1.21.11-2566-0fbf8d2]
at java.base/java.lang.Thread.run(Thread.java:1583) ~[?:?]
Caused by: java.lang.NullPointerException: Cannot read field "triggerTick" because "scheduledTick" is null
at net.minecraft.world.ticks.ScheduledTick.lambda$static$0(ScheduledTick.java:10) ~[purpur-1.21.11.jar:1.21.11-2566-0fbf8d2]
at java.base/java.util.PriorityQueue.siftDownUsingComparator(PriorityQueue.java:712) ~[?:?]
at java.base/java.util.PriorityQueue.poll(PriorityQueue.java:585) ~[?:?]
at net.minecraft.world.ticks.LevelChunkTicks.poll(LevelChunkTicks.java:66) ~[purpur-1.21.11.jar:1.21.11-2566-0fbf8d2]
at net.minecraft.world.ticks.LevelTicks.drainFromCurrentContainer(LevelTicks.java:167) ~[purpur-1.21.11.jar:1.21.11-2566-0fbf8d2]
at net.minecraft.world.ticks.LevelTicks.drainContainers(LevelTicks.java:132) ~[purpur-1.21.11.jar:1.21.11-2566-0fbf8d2]
at net.minecraft.world.ticks.LevelTicks.collectTicks(LevelTicks.java:97) ~[purpur-1.21.11.jar:1.21.11-2566-0fbf8d2]
at net.minecraft.world.ticks.LevelTicks.tick(LevelTicks.java:85) ~[purpur-1.21.11.jar:1.21.11-2566-0fbf8d2]
at net.minecraft.server.level.ServerLevel.tick(ServerLevel.java:820) ~[purpur-1.21.11.jar:1.21.11-2566-0fbf8d2]
at net.minecraft.server.MinecraftServer.tickChildren(MinecraftServer.java:1856) ~[purpur-1.21.11.jar:1.21.11-2566-0fbf8d2]
... 6 more
[21:02:09 ERROR]: This crash report has been saved to: /home/container/crash-reports/crash-2026-03-12_21.02.09-server.txt
[21:02:09 INFO]: Stopping server
[21:02:09 INFO]: [BetterWorldStats] Disabling BetterWorldStats v1.11.0
[21:02:09 INFO]: [PurpurExtras] Disabling PurpurExtras v1.34.4
[21:02:09 INFO]: [ToolStats] Disabling ToolStats v1.9.7
[21:02:09 INFO]: [ServerExtras] Disabling ServerExtras v1.3.6
[21:02:09 INFO]: [TAB] Disabling TAB v5.2.1
[21:02:09 INFO]: [TAB] Disabled in 3ms
[21:02:09 INFO]: [AEF] Disabling AnarchyExploitFixes v2.7.12-SNAPSHOT
[21:02:09 INFO]: [TextDisplay] Disabling TextDisplay v4.1
[21:02:09 INFO]: [LiteEco] Disabling LiteEco v1.7.3-SNAPSHOT
[21:02:09 INFO]: [LiteEco] Unregistering hooks...
[21:02:09 INFO]: [com.zaxxer.hikari.HikariDataSource] LiteEco - Shutdown initiated...
[21:02:09 INFO]: [com.zaxxer.hikari.HikariDataSource] LiteEco - Shutdown completed.
[21:02:09 INFO]: [LiteEco] ✅ Database connection closed cleanly.
[21:02:09 INFO]: [LiteEco] Plugin is disabled
[21:02:09 INFO]: [FairyChat] Disabling FairyChat v0.7.4
[21:02:09 INFO]: [com.zaxxer.hikari.HikariDataSource] FairyChat - Shutdown initiated...
[21:02:09 INFO]: [com.zaxxer.hikari.HikariDataSource] FairyChat - Shutdown completed.
[21:02:09 INFO]: [SignShop] Disabling SignShop v5.2.0
[21:02:09 INFO]: [SignShop] Successfully cancelled async sellers.yml save task with ID: 88
[21:02:09 INFO]: [SignShop] Successfully cancelled async timing.yml save task with ID: 89
[21:02:09 INFO]: [SignShop] Disabled
[21:02:09 INFO]: [LiveMaps] Disabling LiveMaps v2.1
[21:02:09 INFO]: [LiveMaps] LiveMaps disabled.
[21:02:09 INFO]: [PVP Arena] Disabling pvparena v2.0.0
[21:02:09 INFO]: [PVP Arena] disabled (version pvparena v2.0.0)
[21:02:09 INFO]: [MiniMOTD] Disabling MiniMOTD v2.2.2
[21:02:09 INFO]: [AntiPopup] Disabling AntiPopup v12.4
[21:02:09 INFO]: [AntiPopup] Disabled PacketEvents.
[21:02:09 INFO]: [GrimAC] Disabling GrimAC v2.3.73-e8a9855
[21:02:09 INFO]: [GrimAC] Terminating PacketEvents...
[21:02:09 INFO]: [InvSee++] Disabling InvSeePlusPlus v0.30.15
[21:02:09 INFO]: [InventoryRollbackPlus] Disabling InventoryRollbackPlus v1.7.9
[21:02:09 INFO]: [InventoryRollbackPlus] Setting shutdown state
[21:02:09 INFO]: [InventoryRollbackPlus] Saving player inventories...
[21:02:09 INFO]: [InventoryRollbackPlus] Done saving player inventories!
[21:02:09 INFO]: [InventoryRollbackPlus] Plugin is disabled!

Fawe Debugpaste

https://athion.net/ISPaster/paste/view/21218d9d11454a9691258d9b54182e7e

Are you interested in contributing a fix?

Yes

Start by reviewing the FAWE debugpaste and the provided stack trace, then reproduce the crash with the //br smooth 5 5 brush while clicking rapidly or using fastuse on Meteor. Done means the server no longer crashes with the ScheduledTick NullPointerException under that reproduction case.