Minor Experiencing an issue where players can not rejoin the server after leaving. In some instances players simply time out and in some places players quit normally. I personally have been able to reproduce this issue while quitting gracefully.
The issue only presents itself when players log off in certain chunks.
The issue can be rectified by simply loading in the chunk where the player logged off (and is trying to log into).
I am also experiencing other errors with similar verbage, all having to do with ConcurrentModifcationException. I received several similar crashes, and have seen plugins logging similar errors. Attached is a similar looking crash report. Below is the console error thrown when players attempt to rejoin.
While I do have a number of plugins installed, none seem to be responsible for this specific error.
[11:32:55] [Server thread/WARN]: Failed to handle packet for /**.***.***.**:53209[11:32:55] [Server thread/WARN]: Failed to handle packet for /**.***.***.**:53209java.util.ConcurrentModificationException: null at java.util.HashMap$HashIterator.nextNode(HashMap.java:1445) ~[?:1.8.0_211] at java.util.HashMap$KeyIterator.next(HashMap.java:1469) ~[?:1.8.0_211] at java.lang.Iterable.forEach(Iterable.java:74) ~[?:1.8.0_211] at net.minecraft.server.v1_14_R1.ChunkMapDistance.a(SourceFile:132) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.ChunkProviderServer.tickDistanceManager(ChunkProviderServer.java:204) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.ChunkProviderServer.getChunkFutureMainThread(ChunkProviderServer.java:144) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:91) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.World.getChunkAt(World.java:212) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.IWorldReader.getChunkAt(SourceFile:105) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.World.getChunkAt(World.java:207) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.Entity.setLocation(Entity.java:1272) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.PlayerConnection.internalTeleport(PlayerConnection.java:1105) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.PlayerConnection.a(PlayerConnection.java:1067) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.PlayerConnection.a(PlayerConnection.java:1040) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.PlayerConnection.a(PlayerConnection.java:1031) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.PlayerList.a(PlayerList.java:165) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.LoginListener.c(LoginListener.java:149) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.LoginListener.tick(LoginListener.java:53) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.NetworkManager.a(NetworkManager.java:230) ~[spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.ServerConnection.c(ServerConnection.java:119) [spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.MinecraftServer.b(MinecraftServer.java:1080) [spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.DedicatedServer.b(DedicatedServer.java:396) [spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.MinecraftServer.a(MinecraftServer.java:956) [spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at net.minecraft.server.v1_14_R1.MinecraftServer.run(MinecraftServer.java:801) [spigot-1.14.2.jar:git-Spigot-df0eb25-da071ec] at java.lang.Thread.run(Thread.java:748) [?:1.8.0_211][11:32:55] [Server thread/INFO]: Stir_Fry_Beans lost connection: Internal server error