[11:51:15 WARN]: [OneTimeItem] Task #35911 for OneTimeItem v6.8.2 generated an exception
java.lang.ArrayIndexOutOfBoundsException: Index -1 out of bounds for length 36
        at java.util.Arrays$ArrayList.set(Unknown Source) ~[?:?]
        at net.minecraft.server.v1_12_R1.NonNullList.set(SourceFile:51) ~[spigot.jar:git-Paper-1574]
        at net.minecraft.server.v1_12_R1.PlayerInventory.setItem(PlayerInventory.java:455) ~[spigot.jar:git-Paper-1574]
        at org.bukkit.craftbukkit.v1_12_R1.inventory.CraftInventory.setItem(CraftInventory.java:96) ~[spigot.jar:git-Paper-1574]
        at org.bukkit.craftbukkit.v1_12_R1.inventory.CraftInventoryPlayer.setItem(CraftInventoryPlayer.java:64) ~[spigot.jar:git-Paper-1574]
        at com.vk2gpz.onetimeitem.e$a.run(e$a.java:151) ~[?:?]
        at org.bukkit.craftbukkit.v1_12_R1.scheduler.CraftTask.run(CraftTask.java:63) ~[spigot.jar:git-Paper-1574]
        at org.bukkit.craftbukkit.v1_12_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:423) ~[spigot.jar:git-Paper-1574]
        at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:840) ~[spigot.jar:git-Paper-1574]
        at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:423) ~[spigot.jar:git-Paper-1574]
        at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:774) ~[spigot.jar:git-Paper-1574]
        at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:666) ~[spigot.jar:git-Paper-1574]
        at java.lang.Thread.run(Unknown Source) [?:?]