Whenever a player logs onto the world, something at his region seems to crash the server. I am not entirely sure what to make out of it, but it seems to be due to a piston, probably? I also tried to manually delete the chunks inside the region at the position of this player's position at the time of the crash, so I don't have to reset everything at this region.
Either way, here follows the crash output:
-------------------
Description: Exception ticking world
java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextNode(HashMap.java:1445)
at java.util.HashMap$KeyIterator.next(HashMap.java:1469)
at net.minecraft.server.v1_16_R3.WorldServer.notify(WorldServer.java:1227)
at net.minecraft.server.v1_16_R3.World.notifyAndUpdatePhysics(World.java:334)
at net.minecraft.server.v1_16_R3.World.a(World.java:310)
at net.minecraft.server.v1_16_R3.World.setTypeAndData(World.java:225)
at net.minecraft.server.v1_16_R3.World.a(World.java:374)
at net.minecraft.server.v1_16_R3.BlockPiston.a(BlockPiston.java:224)
at net.minecraft.server.v1_16_R3.BlockBase$BlockData.a(BlockBase.java:493)
at net.minecraft.server.v1_16_R3.WorldServer.a(WorldServer.java:1299)
at net.minecraft.server.v1_16_R3.WorldServer.ak(WorldServer.java:1289)
at net.minecraft.server.v1_16_R3.WorldServer.doTick(WorldServer.java:346)
at net.minecraft.server.v1_16_R3.MinecraftServer.b(MinecraftServer.java:1105)
at net.minecraft.server.v1_16_R3.DedicatedServer.b(DedicatedServer.java:355)
at net.minecraft.server.v1_16_R3.MinecraftServer.a(MinecraftServer.java:1008)
at net.minecraft.server.v1_16_R3.MinecraftServer.w(MinecraftServer.java:847)
at net.minecraft.server.v1_16_R3.MinecraftServer.lambda$0(MinecraftServer.java:164)
at java.lang.Thread.run(Thread.java:748)
-------------------
Some details:
– System Details –
Details:
Minecraft Version: 1.16.5
Minecraft Version ID: 1.16.5
Operating System: Linux (amd64) version 4.15.0-124-generic
Java Version: 1.8.0_275, Private Build
Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Private Build
Memory: 2331479352 bytes (2223 MB) / 3092250624 bytes (2949 MB) up to 11453595648 bytes (10923 MB)
CPUs: 4
JVM Flags: 2 total; -Xmx12G -Xms2G
CraftBukkit Information:
Running: CraftBukkit version 2991-Spigot-018b9a0-f3f3094 (MC: 1.16.5) (Implementing API version 1.16.5-R0.1-SNAPSHOT) true
Plugins: {}
Warnings: DEFAULT
Reload Count: 0
-------------------
I thought it might have been due to some plugins, but it also occurs without any plugins... I am not sure, if you need any additional data, but I can offer some up if necessary.
The minimal reproduceable issue can be seen when teleported at the position -606 67 234. It seems to happen ONLY when both regions r.-1.0 and r.-2.0 are present. Removing either one will not trigger this crash.
https://mega.nz/file/Og0EyApQ#LrGp14DqoAOpf0efZTjArUTdTWALoreqlhCluDTA8JE
Apparently, this issue also occurs on Vanilla Minecraft, so I have that one attached, too.
https://mega.nz/file/CgdUQRLQ#awsIVjCwAJ-KBPu5Va_VONnMERBcaHgem3d7I9bDgZU
Thank you for your report!
However, this issue is Invalid.
Your game, launcher or server is modified.
If you can reproduce the issue in a vanilla environment, please recreate the issue.
Any non-standard client/server/launcher build needs to be taken up with the appropriate team, not Mojang.
Any plugin issues need to be addressed to the creator of the plugin or resource pack.
If you have problems on large servers, such as The Hive and Hypixel, please contact them first as they run modified server software.
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