With a friend we tested the 1.10 and we spawn PolarBear and place some Magma Blocks at a moment the serv crash with this error:
[21:09:24] [Server thread/ERROR]: Encountered an unexpected exception
net.minecraft.server.v1_10_R1.ReportedException: Ticking entity
at net.minecraft.server.v1_10_R1.MinecraftServer.D(MinecraftServer.java:815) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.DedicatedServer.D(DedicatedServer.java:399) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.MinecraftServer.C(MinecraftServer.java:672) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.MinecraftServer.run(MinecraftServer.java:571) [Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_60]
Caused by: java.lang.IllegalStateException: Unhandled damage of EntityPolarBear['Polar Bear'/278, l='world', x=-28,33, y=61,00, z=7,65] from hotFloor
at org.bukkit.craftbukkit.v1_10_R1.event.CraftEventFactory.handleEntityDamageEvent(CraftEventFactory.java:559) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at org.bukkit.craftbukkit.v1_10_R1.event.CraftEventFactory.handleLivingEntityDamageEvent(CraftEventFactory.java:602) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityLiving.damageEntity0(EntityLiving.java:1238) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityLiving.damageEntity(EntityLiving.java:834) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.BlockMagma.stepOn(SourceFile:38) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.Entity.move(Entity.java:760) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityLiving.g(EntityLiving.java:1686) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityLiving.n(EntityLiving.java:1988) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityInsentient.n(EntityInsentient.java:512) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityAgeable.n(EntityAgeable.java:150) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityAnimal.n(EntityAnimal.java:25) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityLiving.m(EntityLiving.java:1817) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityInsentient.m(EntityInsentient.java:240) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityPolarBear.m(SourceFile:146) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.World.entityJoinedWorld(World.java:1621) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.World.g(World.java:1596) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.World.tickEntities(World.java:1430) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.WorldServer.tickEntities(WorldServer.java:632) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.MinecraftServer.D(MinecraftServer.java:804) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
... 4 more
[21:09:24] [Server thread/ERROR]: Cause of unexpected exception was
java.lang.IllegalStateException: Unhandled damage of EntityPolarBear['Polar Bear'/278, l='world', x=-28,33, y=61,00, z=7,65] from hotFloor
at org.bukkit.craftbukkit.v1_10_R1.event.CraftEventFactory.handleEntityDamageEvent(CraftEventFactory.java:559) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at org.bukkit.craftbukkit.v1_10_R1.event.CraftEventFactory.handleLivingEntityDamageEvent(CraftEventFactory.java:602) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityLiving.damageEntity0(EntityLiving.java:1238) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityLiving.damageEntity(EntityLiving.java:834) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.BlockMagma.stepOn(SourceFile:38) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.Entity.move(Entity.java:760) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityLiving.g(EntityLiving.java:1686) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityLiving.n(EntityLiving.java:1988) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityInsentient.n(EntityInsentient.java:512) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityAgeable.n(EntityAgeable.java:150) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityAnimal.n(EntityAnimal.java:25) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityLiving.m(EntityLiving.java:1817) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityInsentient.m(EntityInsentient.java:240) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.EntityPolarBear.m(SourceFile:146) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.World.entityJoinedWorld(World.java:1621) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.World.g(World.java:1596) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.World.tickEntities(World.java:1430) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.WorldServer.tickEntities(WorldServer.java:632) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.MinecraftServer.D(MinecraftServer.java:804) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.DedicatedServer.D(DedicatedServer.java:399) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.MinecraftServer.C(MinecraftServer.java:672) ~[Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at net.minecraft.server.v1_10_R1.MinecraftServer.run(MinecraftServer.java:571) [Spigot-v1_10.jar:git-Spigot-da278d1-a8a4bed]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_60]
[21:09:24] [Server thread/ERROR]: This crash report has been saved to: /home/a772014010200104722/27599/./crash-reports/crash-2016-06-10_21.09.24-server.txt
[21:09:24] [Server thread/INFO]: Stopping server
We kill the Polar Bear with MCEdit and it work fine after.
Thank you for your report.
However, your ticket has been resolved as invalid.
This ticket relates to a modified or 3rd party client, server, or launcher.
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.
This site is for addressing issues related to the base unmodded Minecraft; Bukkit/Spigot, Forge, Optifine, modded servers such as The Hive, Overcast, Showbot, Hypixel or any other modded system invalidates your ticket, unless the behavior can be reproduced in Vanilla.
Additionally, if you have problems on large-scale modded servers, please report it to their site. It's probably not a bug in Vanilla Minecraft.
:info: If you are able to reproduce your issue in a vanilla environment, feel free to create a new ticket.