I'm not understanding this error and how to fix it.

31.08 21:08:03 [Disconnect] User K_Craft07 has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User Iron_Fox has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User REDINATOR has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User UltimaZer0MC has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User DogFood_ has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User DemSmashies has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User VivBlop has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User Zingzang14 has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User rosariokids2015 has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User theboss23766 has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User lonewolf1358 has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User ami9996 has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User PokemarioX has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User Thefoxfromfnaf has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User isaminer has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User Samprime516 has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User hugoborracho2003 has disconnected, reason: Server shutting down
31.08 21:08:03 [Disconnect] User Michelle_Schmidt has disconnected, reason: Server shutting down
31.08 21:08:03 [Multicraft] Server stopped
31.08 21:08:03 [Multicraft] Server shut down
31.08 21:08:03 [Server] INFO /run.sh: line 31: 30326 Killed /monitor.sh "$PID" "$USER"
31.08 21:08:03 [Server] INFO Process 30325 detected
31.08 21:08:03 [Server] INFO Process 30325 dead!
31.08 21:08:03 [Multicraft] Skipped 410 lines due to rate limit (30/s)
31.08 21:08:00 [Multicraft] Server ran command Create Backup
31.08 21:07:20 [Server] ERROR com.worldcretornica.plotme_core.bukkit.BukkitServerBridge.getConfig(BukkitServerBridge.java:274)
31.08 21:07:20 [Server] ERROR org.bukkit.configuration.file.FileConfiguration.load(FileConfiguration.java:169)
31.08 21:07:20 [Server] ERROR org.bukkit.configuration.file.FileConfiguration.load(FileConfiguration.java:226)
31.08 21:07:20 [Server] ERROR org.bukkit.configuration.file.YamlConfiguration.loadFromString(YamlConfiguration.java:55)
31.08 21:07:20 [Server] ERROR org.yaml.snakeyaml.Yaml.load(Yaml.java:369)
31.08 21:07:20 [Server] ERROR org.yaml.snakeyaml.Yaml.loadFromReader(Yaml.java:450)
31.08 21:07:20 [Server] ERROR org.yaml.snakeyaml.constructor.BaseConstructor.getSingleData(BaseConstructor.java:127)
31.08 21:07:20 [Server] ERROR org.yaml.snakeyaml.constructor.BaseConstructor.constructDocument(BaseConstructor.java:141)
31.08 21:07:20 [Server] ERROR org.yaml.snakeyaml.constructor.BaseConstructor.constructObject(BaseConstructor.java:182)
31.08 21:07:20 [Server] ERROR org.bukkit.configuration.file.YamlConstructor$ConstructCustomObject.construct(YamlConstructor.java:26)
31.08 21:07:20 [Server] ERROR org.yaml.snakeyaml.constructor.SafeConstructor$ConstructYamlMap.construct(SafeConstructor.java:489)
31.08 21:07:20 [Server] ERROR org.yaml.snakeyaml.constructor.BaseConstructor.constructMapping(BaseConstructor.java:354)
31.08 21:07:20 [Server] ERROR org.yaml.snakeyaml.constructor.SafeConstructor.constructMapping2ndStep(SafeConstructor.java:147)
31.08 21:07:20 [Server] ERROR org.yaml.snakeyaml.constructor.BaseConstructor.constructMapping2ndStep(BaseConstructor.java:373)
31.08 21:07:20 [Server] ERROR org.yaml.snakeyaml.constructor.BaseConstructor.constructObject(BaseConstructor.java:173)
31.08 21:07:20 [Server] ERROR java.util.HashMap.containsKey(HashMap.java:449)
31.08 21:07:20 [Server] ERROR java.util.HashMap.getEntry(HashMap.java:462)
31.08 21:07:20 [Server] ERROR java.util.HashMap.hash(HashMap.java:362)
31.08 21:07:20 [Server] ERROR org.yaml.snakeyaml.nodes.Node.hashCode(Node.java:134)
31.08 21:07:20 [Server] ERROR java.lang.Object.hashCode(Native Method)
31.08 21:07:20 [Server] ERROR Stack:
31.08 21:07:20 [Server] ERROR PID: 14 | Suspended: false | Native: false | State: RUNNABLE
31.08 21:07:20 [Server] ERROR Current Thread: Server thread
31.08 21:07:20 [Server] ERROR ------------------------------
31.08 21:07:20 [Server] ERROR Server thread dump (Look for plugins here before reporting to Spigot!):
31.08 21:07:20 [Server] ERROR ------------------------------
31.08 21:07:20 [Server] ERROR Spigot version: git-Spigot-fdc1440-53fac9f (MC: 1.8.8)
31.08 21:07:20 [Server] ERROR Be sure to include ALL relevant console errors and Minecraft crash reports
31.08 21:07:20 [Server] ERROR Please report this to http://www.spigotmc.org/
31.08 21:07:20 [Server] ERROR The server has stopped responding!
31.08 21:06:50 [Server] INFO UUID of player REDINATOR is 7e58aead-171f-4581-b258-9efaadb11651
31.08 21:06:49 [Server] INFO UUID of player megan_poop is c086998a-0c34-47f6-8fba-9ba2cb24014e
31.08 21:06:36 [Server] INFO GroupManager - INFO - Data files refreshed.
31.08 21:06:29 [Server] INFO UUID of player Samprime516 is b68bdf1e-86cd-4622-bb75-d6cd3bfc526e
31.08 21:06:17 [Multicraft] Thefoxfromfnaf ran command Message of the Day
31.08 21:06:17 [Connect] User Thefoxfromfnaf, IP 174.21.225.245
31.08 21:06:17 [Server] INFO DeadlyBFDIFirey was killed by Withered Freddy
31.08 21:06:17 [Disconnect] User DeadlyBFDIFirey has disconnected, reason: Disconnected
31.08 21:06:09 [Server] INFO UUID of player Thefoxfromfnaf is 9658f23d-318f-4554-b425-0499592f1eca
31.08 21:05:53 [Server] INFO Queue overloaded. Size: 340936
31.08 21:05:49 [Server] INFO Queue overloaded. Size: 350554
31.08 21:05:46 [Server] INFO Queue overloaded. Size: 360001
31.08 21:05:42 [Server] INFO Queue overloaded. Size: 368910
31.08 21:05:39 [Server] INFO Queue overloaded. Size: 377617
31.08 21:05:35 [Server] INFO Queue overloaded. Size: 386553
31.08 21:05:32 [Server] INFO Thefoxfromfnaf was killed by Withered Freddy
31.08 21:05:32 [Disconnect] User Thefoxfromfnaf has disconnected, reason: Disconnected
31.08 21:05:32 [Server] INFO Queue overloaded. Size: 395605
31.08 21:05:29 [Server] INFO Queue overloaded. Size: 403074
31.08 21:05:26 [Server] INFO T-Admin: [T-Admin]-NightmareSam
31.08 21:05:26 [Server] INFO Default: [Player]-1CatWoman1, [Player]-Looy3, [Player]-MoshiMonstersDrStranglove, [Player]-YouHaveBeenSpookedByTheSpookySkeleton, [Player]hapdog7, [Player]K_Craft07, [Player]lonewolf1358, [Player]Michelle_Schmidt, [Player]Thefoxfromfnaf, [Player]VivBlop, [Player]Zingzang14, [Player]ami9996, [Player]DogFood_, [Player]hugoborracho2003, [Player]isaminer, [Player]PokemarioX, [Player]-Sam_Gladiator
31.08 21:05:25 [Server] INFO Queue overloaded. Size: 410726
31.08 21:05:22 [Server] INFO Queue overloaded. Size: 415574
31.08 21:05:18 [Server] INFO Queue overloaded. Size: 424402
31.08 21:05:18 [Server] INFO DeadlyBFDIFirey was welcomed by Toy Freddy
31.08 21:05:18 [Server] INFO Player: DeadlyBFDIFirey has 0 votes
31.08 21:05:18 [Multicraft] DeadlyBFDIFirey ran command Message of the Day
31.08 21:05:18 [Connect] User DeadlyBFDIFirey, IP 76.64.119.189
31.08 21:05:18 [Server] INFO UUID of player DeadlyBFDIFirey is 55c90844-8dcc-477e-8458-25efe538db04
31.08 21:05:16 [Server] INFO Queue overloaded. Size: 432736
31.08 21:05:14 [Server] INFO Queue overloaded. Size: 441447
31.08 21:05:12 [Server] INFO Queue overloaded. Size: 448411
31.08 21:05:10 [Server] INFO Queue overloaded. Size: 456531
31.08 21:05:08 [Server] INFO Queue overloaded. Size: 465140
31.08 21:05:07 [Server] INFO Queue overloaded. Size: 472364
31.08 21:04:56 [Server] INFO Lag Notice - Slow Permissions System (GroupManager) Response - Request took over 30.269ms!
31.08 21:04:53 [Server] INFO Queue overloaded. Size: 458517
31.08 21:04:50 [Server] INFO Queue overloaded. Size: 457434
31.08 21:04:48 [Server] INFO Queue overloaded. Size: 460775
31.08 21:04:46 [Server] INFO Queue overloaded. Size: 467441
31.08 21:04:44 [Server] INFO Queue overloaded. Size: 475938
31.08 21:04:42 [Server] INFO Queue overloaded. Size: 483413
31.08 21:04:40 [Server] INFO Queue overloaded. Size: 491754
31.08 21:04:38 [Server] INFO Queue overloaded. Size: 499567
31.08 21:04:36 [Server] INFO Queue overloaded. Size: 507476
31.08 21:04:34 [Server] INFO Queue overloaded. Size: 517106
31.08 21:04:32 [Server] INFO Queue overloaded. Size: 523489
31.08 21:04:30 [Server] INFO Queue overloaded. Size: 532554
31.08 21:04:28 [Server] INFO Queue overloaded. Size: 541546
31.08 21:04:26 [Server] INFO Queue overloaded. Size: 550104
31.08 21:04:24 [Server] INFO lonewolf1358 was welcomed by Toy Freddy
31.08 21:04:24 [Server] INFO Player: lonewolf1358 has 0 votes
31.08 21:04:24 [Multicraft] lonewolf1358 ran command Message of the Day
31.08 21:04:24 [Connect] User lonewolf1358, IP 75.128.184.233
31.08 21:04:24 [Server] INFO UUID of player lonewolf1358 is 54e8d6d7-cb65-45dd-9369-cf7f9a8c7855
31.08 21:04:24 [Server] INFO Queue overloaded. Size: 558798
31.08 21:04:24 [Server] INFO T-Admin: [T-Admin]-NightmareSam
31.08 21:04:24 [Server] INFO Default: [Player]-1CatWoman1, [Player]-Looy3, [Player]-Sam_Gladiator, [Player]-YouHaveBeenSpookedByTheSpookySkeleton, [Player]DogFood_, [Player]hapdog7, [Player]hugoborracho2003, [Player]isaminer, [Player]K_Craft07, [Player]Michelle_Schmidt, [Player]Thefoxfromfnaf, [Player]VivBlop, [Player]Zingzang14, [Player]ami9996, [Player]PokemarioX
31.08 21:04:22 [Server] INFO Queue overloaded. Size: 564534
31.08 21:04:20 [Server] INFO Queue overloaded. Size: 572392
31.08 21:04:18 [Server] INFO lonewolf1358 was killed by Withered Freddy
31.08 21:04:18 [Disconnect] User lonewolf1358 has disconnected, reason: Internal Exception: io.netty.handler.codec.DecoderException: The received encoded string buffer length is longer than maximum allowed (32767 > 1536)
31.08 21:04:18 [Server] INFO Queue overloaded. Size: 580768