Server crash - ConcurrentModificationException at ServerDebugSubscribers.tick (1.21.11)

Stack trace

[15:32:05] [Folia Region Scheduler Thread #7/ERROR]: [io.papermc.paper.threadedregions.TickRegionScheduler] Region #920922 centered at chunk [-752, -816] in world 'survival' failed to tick:
java.util.ConcurrentModificationException
	at java.base/java.util.HashMap$HashIterator.remove(HashMap.java:1620) ~[?:?]
	at java.base/java.util.Collection.removeIf(Collection.java:582) ~[?:?]
	at net.minecraft.util.debug.ServerDebugSubscribers.tick(ServerDebugSubscribers.java:35) ~[folia-1.21.11.jar:1.21.11-14-529aabc]
	at net.minecraft.server.MinecraftServer.tickChildren(MinecraftServer.java:1946) ~[folia-1.21.11.jar:1.21.11-14-529aabc]
	at net.minecraft.server.MinecraftServer.tickServer(MinecraftServer.java:1740) ~[folia-1.21.11.jar:1.21.11-14-529aabc]
	at net.minecraft.server.dedicated.DedicatedServer.tickServer(DedicatedServer.java:429) ~[folia-1.21.11.jar:1.21.11-14-529aabc]
	at io.papermc.paper.threadedregions.TickRegions$ConcreteRegionTickHandle.tickRegion(TickRegions.java:485) ~[folia-1.21.11.jar:1.21.11-14-529aabc]
	at io.papermc.paper.threadedregions.TickRegionScheduler$RegionScheduleHandle.runTick(TickRegionScheduler.java:481) ~[folia-1.21.11.jar:1.21.11-14-529aabc]
	at ca.spottedleaf.concurrentutil.scheduler.EDFSchedulerThreadPool$TickThreadRunner.run(EDFSchedulerThreadPool.java:526) ~[concurrentutil-0.0.8.jar:?]
	at java.base/java.lang.Thread.run(Thread.java:1474) ~[?:?]
[15:32:05] [Region shutdown thread/INFO]: [RegionShutdownThread] Awaiting scheduler termination for 60s...
[15:32:05] [Region shutdown thread/INFO]: [RegionShutdownThread] Scheduler halted
[15:32:05] [Region shutdown thread/INFO]: Stopping server

Plugin and Datapack List

[15:53:55 INFO]: ℹ Server Plugins (73):
[15:53:55 INFO]: Paper Plugins (8):
[15:53:55 INFO]: - BASZ-LimitDrop, BASZ-Shutdown, ChatGames, FancyHolograms, FancyNpcs, Nexo, NexoAddon, Worlds
[15:53:55 INFO]: Bukkit Plugins (65):
[15:53:55 INFO]: - ajLeaderboards, Apollo-Folia, AuraSkills, AxPlayerWarps, AxTrade, BASZ-AC, BASZ-AuctionHouse, BASZ-CHAT, BASZ-ChatLink, BASZ-CheckShort
[15:53:55 INFO]: BASZ-Coinflip, BASZ-COMBAT, BASZ-CORE, BASZ-CosmeticsSkin, BASZ-item-transaction, BASZ-Jail, BASZ-Label, BASZ-LINKDC-folia, BASZ-MC-Amethyst, BASZ-MC-BOSS
[15:53:55 INFO]: BASZ-MC-Orders, BASZ-MC-PsSetting, BASZ-MC-SELL, BASZ-MC-Shop, BASZ-MobCatcher, BASZ-NoMoreCollision, BASZ-Patch, BASZ-PlayerTexture, BASZ-PrivateChests, BASZ-Spawner
[15:53:55 INFO]: BASZCrossSync, BASZTeam, BetterBounty, BlueSpoof, ChatHeadFont, Chunky, CMILib, DonutCrates, Essentials, EssentialsSpawn
[15:53:55 INFO]: FakePlayer, floodgate, ItemEdit, LPC, LuckPerms, MailboxPlugin, ODailyQuests, packetevents, PhoenixCrates, PlaceholderAPI
[15:53:55 INFO]: PlugManX, ProtectionStones, PSAnvilGUI, QuickShop-Hikari, SkinsRestorer, spark, SpawnFix, TAB, Vault, ViaVersion
[15:53:55 INFO]: voicechat, WorldEdit, WorldGuard, WorldGuardExtraFlagsPlus, zMenu

Actions to reproduce (if known)

No response

Folia version

Folia 1.21.11-14

Other

No response

Start at net.minecraft.util.debug.ServerDebugSubscribers.tick, the entry point named in the stack trace, and inspect how the reported Collection.removeIf call is reached during MinecraftServer.tickChildren. Reproduce the crash with Folia 1.21.11-14 if possible using the supplied server context; done means the server no longer terminates with this ConcurrentModificationException and the failure path is covered by an appropriate regression check.