[20:45:18] [Server thread/INFO]: Starting minecraft server version 1.7.10
[20:46:03] [Server thread/INFO]: Loading properties
[20:46:03] [Server thread/INFO]: Default game type: SURVIVAL
[20:46:03] [Server thread/INFO]: Generating keypair
[20:46:03] [Server thread/INFO]: Starting Minecraft server on *:25565
[20:46:30] [Server thread/INFO]: Preparing level "world"
[20:46:33] [Server thread/INFO]: Preparing start region for level 0
[20:46:33] [Server thread/INFO]: Done (3,812s)! For help, type "help" or "?"
[20:46:37] [Server thread/ERROR]: Encountered an unexpected exception
net.minecraft.util.ReportedException: Ticking block entity
	at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:642) ~[MinecraftServer.class:?]
	at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:334) ~[lt.class:?]
	at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:547) ~[MinecraftServer.class:?]
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:396) [MinecraftServer.class:?]
	at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685) [li.class:?]
Caused by: java.util.ConcurrentModificationException
	at java.util.ArrayList$Itr.checkForComodification(Unknown Source) ~[?:1.8.0_191]
	at java.util.ArrayList$Itr.remove(Unknown Source) ~[?:1.8.0_191]
	at net.minecraft.world.World.func_147455_a(World.java:2586) ~[ahb.class:?]
	at WayofTime.alchemicalWizardry.common.block.BlockTeleposer.swapBlocks(BlockTeleposer.java:216) ~[BlockTeleposer.class:1.7.10-1.3.3-17]
	at WayofTime.alchemicalWizardry.common.block.BlockTeleposer.swapBlocks(BlockTeleposer.java:156) ~[BlockTeleposer.class:1.7.10-1.3.3-17]
	at WayofTime.alchemicalWizardry.common.tileEntity.TETeleposer.func_145845_h(TETeleposer.java:137) ~[TETeleposer.class:1.7.10-1.3.3-17]
	at net.minecraft.world.World.func_72939_s(World.java:1939) ~[ahb.class:?]
	at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:489) ~[mt.class:?]
	at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:636) ~[MinecraftServer.class:?]
	... 4 more
[20:46:37] [Server thread/ERROR]: This crash report has been saved to: C:\Users\strom\Desktop\MC server 2\.\crash-reports\crash-2019-07-20_20.46.37-server.txt
[20:46:37] [Server thread/INFO]: Stopping server
[20:46:37] [Server thread/INFO]: Saving players
[20:46:37] [Server thread/INFO]: Saving worlds
[20:46:37] [Server thread/INFO]: Saving chunks for level 'world'/Overworld
[20:46:38] [Server thread/INFO]: Saving chunks for level 'world'/Nether
[20:46:38] [Server thread/INFO]: Saving chunks for level 'world'/The End
[20:46:38] [Server thread/INFO]: Saving chunks for level 'world'/Twilight Forest
[20:46:38] [Server thread/INFO]: Saving chunks for level 'world'/Underdark
[20:46:38] [Server thread/INFO]: Saving chunks for level 'world'/Dungeon
[20:46:38] [Server thread/INFO]: Saving chunks for level 'world'/Spirit World
[20:46:38] [Server thread/INFO]: Saving chunks for level 'world'/Torment
[20:46:38] [Server thread/INFO]: Saving chunks for level 'world'/Mirror
[20:46:38] [Server thread/INFO]: Saving chunks for level 'world'/The Outer Lands
[20:46:38] [Server thread/INFO]: Saving chunks for level 'world'/Bedrock
[20:46:38] [Server thread/INFO]: Saving chunks for level 'world'/The Last Millenium
[20:46:38] [Server thread/INFO]: Saving chunks for level 'world'/Mining World