java.lang.IllegalArgumentException: bound must be positive
        at java.util.Random.nextInt(Unknown Source) ~[?:1.8.0_111]
        at fr.crafttim.skywars.chest.ItemRandom.getRandomItem(ItemRandom.java:85) ~[?:?]
        at fr.crafttim.skywars.chest.ChestRefill.refillAllChests(ChestRefill.java:24) ~[?:?]
        at fr.crafttim.skywars.game.PreGameManager$1.run(PreGameManager.java:37) ~[?:?]
        at org.bukkit.craftbukkit.v1_9_R2.scheduler.CraftTask.run(CraftTask.java:71) ~[spigot-1.9.jar:git-Spigot-4af49dc-c5e9a16]
        at org.bukkit.craftbukkit.v1_9_R2.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:350) [spigot-1.9.jar:git-Spigot-4af49dc-c5e9a16]
        at net.minecraft.server.v1_9_R2.MinecraftServer.D(MinecraftServer.java:734) [spigot-1.9.jar:git-Spigot-4af49dc-c5e9a16]
        at net.minecraft.server.v1_9_R2.DedicatedServer.D(DedicatedServer.java:399) [spigot-1.9.jar:git-Spigot-4af49dc-c5e9a16]
        at net.minecraft.server.v1_9_R2.MinecraftServer.C(MinecraftServer.java:665) [spigot-1.9.jar:git-Spigot-4af49dc-c5e9a16]
        at net.minecraft.server.v1_9_R2.MinecraftServer.run(MinecraftServer.java:564) [spigot-1.9.jar:git-Spigot-4af49dc-c5e9a16]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_111]
[17:45:33 WARN]: [SkyWars] Task #11 for SkyWars v1.0 generated an exception
java.lang.IllegalArgumentException: bound must be positive
        at java.util.Random.nextInt(Unknown Source) ~[?:1.8.0_111]
        at fr.crafttim.skywars.chest.ItemRandom.getRandomItem(ItemRandom.java:85) ~[?:?]
        at fr.crafttim.skywars.chest.ChestRefill.refillAllChests(ChestRefill.java:24) ~[?:?]
        at fr.crafttim.skywars.game.GameManager$1.run(GameManager.java:44) ~[?:?]
        at org.bukkit.craftbukkit.v1_9_R2.scheduler.CraftTask.run(CraftTask.java:71) ~[spigot-1.9.jar:git-Spigot-4af49dc-c5e9a16]
        at org.bukkit.craftbukkit.v1_9_R2.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:350) [spigot-1.9.jar:git-Spigot-4af49dc-c5e9a16]
        at net.minecraft.server.v1_9_R2.MinecraftServer.D(MinecraftServer.java:734) [spigot-1.9.jar:git-Spigot-4af49dc-c5e9a16]
        at net.minecraft.server.v1_9_R2.DedicatedServer.D(DedicatedServer.java:399) [spigot-1.9.jar:git-Spigot-4af49dc-c5e9a16]
        at net.minecraft.server.v1_9_R2.MinecraftServer.C(MinecraftServer.java:665) [spigot-1.9.jar:git-Spigot-4af49dc-c5e9a16]
        at net.minecraft.server.v1_9_R2.MinecraftServer.run(MinecraftServer.java:564) [spigot-1.9.jar:git-Spigot-4af49dc-c5e9a16]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_111]