[15:16:58] [Server thread/ERROR]: #!#! [Skript] Severe Error:
[15:16:58] [Server thread/ERROR]: #!#!
[15:16:58] [Server thread/ERROR]: #!#! Something went horribly wrong with Skript.
[15:16:58] [Server thread/ERROR]: #!#! This issue is NOT your fault! You probably can't fix it yourself, either.
[15:16:58] [Server thread/ERROR]: #!#! It looks like you are using some plugin(s) that alter how Skript works (addons).
[15:16:58] [Server thread/ERROR]: #!#! Here is full list of them:
[15:16:58] [Server thread/ERROR]: #!#! TuSKe (github.com/Tuke-Nuke/TuSKe) HydraDb
[15:16:58] [Server thread/ERROR]: #!#! We could not identify which of those are specially related, so this might also be Skript issue.
[15:16:58] [Server thread/ERROR]: #!#! You should try disabling those plugins one by one, trying to find which one causes it.
[15:16:58] [Server thread/ERROR]: #!#! If the error doesn't disappear even after disabling all listed plugins, it is probably Skript issue.
[15:16:58] [Server thread/ERROR]: #!#! In that case, you will be given instruction on how should you report it.
[15:16:58] [Server thread/ERROR]: #!#! On the other hand, if the error disappears when disabling some plugin, report it to author of that plugin.
[15:16:58] [Server thread/ERROR]: #!#! Only if the author tells you to do so, report it to Skript's issue tracker.
[15:16:58] [Server thread/ERROR]: #!#!
[15:16:58] [Server thread/ERROR]: #!#! Stack trace:
[15:16:58] [Server thread/ERROR]: #!#! java.lang.ClassCastException: java.util.HashMap cannot be cast to java.util.WeakHashMap
[15:16:58] [Server thread/ERROR]: #!#!     at com.github.tukenuke.tuske.util.VariableUtil.<init>(VariableUtil.java:24)
[15:16:58] [Server thread/ERROR]: #!#!     at com.github.tukenuke.tuske.util.VariableUtil.getInstance(VariableUtil.java:17)
[15:16:58] [Server thread/ERROR]: #!#!     at com.github.tukenuke.tuske.sections.gui.EffMakeGUI.execute(EffMakeGUI.java:77)
[15:16:58] [Server thread/ERROR]: #!#!     at com.github.tukenuke.tuske.util.EffectSection.check(EffectSection.java:54)
[15:16:58] [Server thread/ERROR]: #!#!     at ch.njol.skript.lang.Condition.run(Condition.java:56)
[15:16:58] [Server thread/ERROR]: #!#!     at ch.njol.skript.lang.Conditional.walk(Conditional.java:51)
[15:16:58] [Server thread/ERROR]: #!#!     at ch.njol.skript.lang.TriggerItem.walk(TriggerItem.java:89)
[15:16:58] [Server thread/ERROR]: #!#!     at ch.njol.skript.effects.Delay$1.run(Delay.java:109)
[15:16:58] [Server thread/ERROR]: #!#!     at org.bukkit.craftbukkit.v1_15_R1.scheduler.CraftTask.run(CraftTask.java:81)
[15:16:58] [Server thread/ERROR]: #!#!     at org.bukkit.craftbukkit.v1_15_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:400)
[15:16:58] [Server thread/ERROR]: #!#!     at net.minecraft.server.v1_15_R1.MinecraftServer.b(MinecraftServer.java:1036)
[15:16:58] [Server thread/ERROR]: #!#!     at net.minecraft.server.v1_15_R1.DedicatedServer.b(DedicatedServer.java:406)
[15:16:58] [Server thread/ERROR]: #!#!     at net.minecraft.server.v1_15_R1.MinecraftServer.a(MinecraftServer.java:984)
[15:16:58] [Server thread/ERROR]: #!#!     at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:824)
[15:16:58] [Server thread/ERROR]: #!#!     at java.lang.Thread.run(Thread.java:748)
[15:16:58] [Server thread/ERROR]: #!#!
[15:16:58] [Server thread/ERROR]: #!#! Version Information:
[15:16:58] [Server thread/ERROR]: #!#!   Skript: 2.4.1 (latest)
[15:16:58] [Server thread/ERROR]: #!#!     Flavor: skriptlang-github
[15:16:58] [Server thread/ERROR]: #!#!     Date: 2019-12-22
[15:16:58] [Server thread/ERROR]: #!#!   Bukkit: 1.15.2-R0.1-SNAPSHOT
[15:16:58] [Server thread/ERROR]: #!#!   Minecraft: 1.15.2
[15:16:58] [Server thread/ERROR]: #!#!   Java: 1.8.0_242 (OpenJDK 64-Bit Server VM 25.242-b08)
[15:16:58] [Server thread/ERROR]: #!#!   OS: Linux amd64 4.9.0-6-amd64
[15:16:58] [Server thread/ERROR]: #!#!
[15:16:58] [Server thread/ERROR]: #!#! Server platform: Spigot
[15:16:58] [Server thread/ERROR]: #!#!
[15:16:58] [Server thread/ERROR]: #!#! Current node: null
[15:16:58] [Server thread/ERROR]: #!#! Current item: make  a gui slot [[long:2]] of gui with ([[itemtype:diamond sword]] named "PVP" >> ch.njol.skript.classes.data.DefaultConverters$13@3f7ed97c: itemtype -> itemstack)
[15:16:58] [Server thread/ERROR]: #!#! Current trigger: script load (script load) (grades.sk, line 1)
[15:16:58] [Server thread/ERROR]: #!#!
[15:16:58] [Server thread/ERROR]: #!#! Thread: Server thread
[15:16:58] [Server thread/ERROR]: #!#!
[15:16:58] [Server thread/ERROR]: #!#! Language: english
[15:16:58] [Server thread/ERROR]: #!#! Link parse mode: DISABLED
[15:16:58] [Server thread/ERROR]: #!#!
[15:16:58] [Server thread/ERROR]: #!#! End of Error.
[15:16:58] [Server thread/ERROR]: #!#!