The console outputed error:Could not pass event ChunkLoadEvent to plugin.And the server crashed..At first,I thought it was a plugin issue.But later,by disabling plugins,I found that were more than one plugin that could trigger this error...All plugins have been updated to the 1.21.6 supported version...Will spigot version 1.21.6 be updated in the future to fix bugs?

The error message(it shows that more than one plugin has triggered the same error):
[20:25:59] [Server thread/ERROR]: Could not pass event ChunkLoadEvent to EliteMobs v9.5.3
org.bukkit.event.EventException: null
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[spigot-api-1.21.6-R0.1-SNAPSHOT.jar:?]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[spigot-api-1.21.6-R0.1-SNAPSHOT.jar:?]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:601) ~[spigot-api-1.21.6-R0.1-SNAPSHOT.jar:?]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:588) ~[spigot-api-1.21.6-R0.1-SNAPSHOT.jar:?]
at net.minecraft.world.level.chunk.Chunk.loadCallback(Chunk.java:600) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.PlayerChunk.lambda$updateFutures$10(PlayerChunk.java:416) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.PlayerChunkMap$CallbackExecutor.run(PlayerChunkMap.java:173) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.PlayerChunk.callEventIfUnloading(PlayerChunk.java:348) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.ChunkMapDistance.a(ChunkMapDistance.java:83) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.ChunkProviderServer.t(ChunkProviderServer.java:308) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.ChunkProviderServer.c(ChunkProviderServer.java:265) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.ChunkProviderServer.a(ChunkProviderServer.java:164) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.world.level.World.a(World.java:303) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at org.bukkit.craftbukkit.v1_21_R5.CraftWorld.getChunkAt(CraftWorld.java:219) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at org.bukkit.craftbukkit.v1_21_R5.CraftChunk.getEntities(CraftChunk.java:127) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at com.magmaguy.elitemobs.CrashFix.delayedChunkCheck(CrashFix.java:65) ~[?:?]
at com.magmaguy.elitemobs.CrashFix.onChunkLoad(CrashFix.java:85) ~[?:?]
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[?:?]
at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[?:?]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot-api-1.21.6-R0.1-SNAPSHOT.jar:?]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[spigot-api-1.21.6-R0.1-SNAPSHOT.jar:?]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:601) ~[spigot-api-1.21.6-R0.1-SNAPSHOT.jar:?]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:588) ~[spigot-api-1.21.6-R0.1-SNAPSHOT.jar:?]
at net.minecraft.world.level.chunk.Chunk.loadCallback(Chunk.java:600) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.PlayerChunk.lambda$updateFutures$10(PlayerChunk.java:416) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.PlayerChunkMap$CallbackExecutor.run(PlayerChunkMap.java:173) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.PlayerChunk.callEventIfUnloading(PlayerChunk.java:348) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.ChunkMapDistance.a(ChunkMapDistance.java:83) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.ChunkProviderServer.t(ChunkProviderServer.java:308) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.ChunkProviderServer$a.B(ChunkProviderServer.java:696) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.ChunkProviderServer.d(ChunkProviderServer.java:304) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.MinecraftServer.bv(MinecraftServer.java:1280) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.MinecraftServer.B(MinecraftServer.java:1268) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.util.thread.IAsyncTaskHandler.b(SourceFile:147) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.MinecraftServer.b(MinecraftServer.java:1225) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.MinecraftServer.w_(MinecraftServer.java:1235) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.MinecraftServer.y(MinecraftServer.java:1078) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:327) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at java.base/java.lang.Thread.run(Thread.java:1583) [?:?]
Caused by: java.lang.NullPointerException: Cannot invoke "it.unimi.dsi.fastutil.objects.ReferenceArrayList.get(int)" because "this.wrapped" is null
at it.unimi.dsi.fastutil.objects.ReferenceOpenHashSet$SetIterator.next(ReferenceOpenHashSet.java:520) ~[fastutil-8.5.15.jar:?]
at net.minecraft.server.level.ChunkMapDistance.a(ChunkMapDistance.java:82) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.ChunkProviderServer.t(ChunkProviderServer.java:308) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.ChunkProviderServer.c(ChunkProviderServer.java:265) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.server.level.ChunkProviderServer.a(ChunkProviderServer.java:164) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at net.minecraft.world.level.World.a(World.java:303) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at org.bukkit.craftbukkit.v1_21_R5.CraftWorld.getChunkAt(CraftWorld.java:219) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at org.bukkit.craftbukkit.v1_21_R5.CraftChunk.getEntities(CraftChunk.java:127) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4518-Spigot-d5ca3f8-98f7fa2]
at com.magmaguy.elitemobs.CrashFix.delayedChunkCheck(CrashFix.java:65) ~[?:?]
at com.magmaguy.elitemobs.CrashFix.onChunkLoad(CrashFix.java:85) ~[?:?]
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[?:?]
at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[?:?]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot-api-1.21.6-R0.1-SNAPSHOT.jar:?]
... 38 more
Another plugin will also be triggered..
Could not pass event ChunkLoadEvent to ImageFrame v1.8.4.0
org.bukkit.event.EventException: null
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[spigot-api-1.21.6-R0.1-SNAPSHOT.jar:?]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[spigot-api-1.21.6-R0.1-SNAPSHOT.jar:?]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:601) ~[spigot-api-1.21.6-R0.1-SNAPSHOT.jar:?]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:588) ~[spigot-api-1.21.6-R0.1-SNAPSHOT.jar:?]
at net.minecraft.world.level.chunk.Chunk.loadCallback(Chunk.java:600) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.server.level.PlayerChunk.lambda$updateFutures$10(PlayerChunk.java:416) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.server.level.PlayerChunkMap$CallbackExecutor.run(PlayerChunkMap.java:173) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.server.level.PlayerChunk.callEventIfUnloading(PlayerChunk.java:348) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.server.level.ChunkMapDistance.a(ChunkMapDistance.java:83) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.server.level.ChunkProviderServer.t(ChunkProviderServer.java:308) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.server.level.ChunkProviderServer$a.B(ChunkProviderServer.java:696) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.server.level.ChunkProviderServer.d(ChunkProviderServer.java:304) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.server.MinecraftServer.bv(MinecraftServer.java:1280) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.server.MinecraftServer.B(MinecraftServer.java:1268) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.util.thread.IAsyncTaskHandler.bA(SourceFile:123) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.server.MinecraftServer.w_(MinecraftServer.java:1231) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.server.MinecraftServer.y(MinecraftServer.java:1078) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:327) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at java.base/java.lang.Thread.run(Thread.java:1583) [?:?]
Caused by: java.lang.NullPointerException: Cannot invoke "it.unimi.dsi.fastutil.objects.ReferenceArrayList.get(int)" because "this.wrapped" is null
at it.unimi.dsi.fastutil.objects.ReferenceOpenHashSet$SetIterator.next(ReferenceOpenHashSet.java:520) ~[fastutil-8.5.15.jar:?]
at net.minecraft.server.level.ChunkMapDistance.a(ChunkMapDistance.java:82) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.server.level.ChunkProviderServer.t(ChunkProviderServer.java:308) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.server.level.ChunkProviderServer.c(ChunkProviderServer.java:265) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.server.level.ChunkProviderServer.a(ChunkProviderServer.java:164) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at net.minecraft.world.level.World.a(World.java:303) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at org.bukkit.craftbukkit.v1_21_R5.CraftWorld.getChunkAt(CraftWorld.java:219) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at org.bukkit.craftbukkit.v1_21_R5.CraftChunk.getEntities(CraftChunk.java:127) ~[spigot-1.21.6-R0.1-SNAPSHOT.jar:4514-Spigot-d5ca3f8-a720008]
at com.loohp.imageframe.objectholders.AnimatedFakeMapManager.lambda$onChunkLoad$18(AnimatedFakeMapManager.java:318) ~[?:?]
at com.loohp.interactivechat.libs.com.loohp.platformscheduler.platform.bukkit.BukkitScheduler.executeOrScheduleSync(BukkitScheduler.java:84) ~[?:?]
at com.loohp.interactivechat.libs.com.loohp.platformscheduler.platform.bukkit.BukkitScheduler.executeOrScheduleSync(BukkitScheduler.java:107) ~[?:?]
at com.loohp.interactivechat.libs.com.loohp.platformscheduler.Scheduler.executeOrScheduleSync(Scheduler.java:126) ~[?:?]
at com.loohp.imageframe.objectholders.AnimatedFakeMapManager.onChunkLoad(AnimatedFakeMapManager.java:317) ~[?:?]
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[?:?]
at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[?:?]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot-api-1.21.6-R0.1-SNAPSHOT.jar:?]
... 18 more