[00:20:14 ERROR]: [JPremium] Plugin JPremium vCLEARED-Backend-1.12.3 has failed to register events for class com.jakub.jpremium.backend.b.b.d because org/bukkit/event/player/PlayerSwapHandItemsEvent does not exist.
[00:20:14 WARN]: java.lang.ArrayIndexOutOfBoundsException: Index 1 out of bounds for length 1

[00:20:14 WARN]:        at com.jakub.jpremium.backend.b.a.e(Unknown Source)

[00:20:14 WARN]:        at com.jakub.jpremium.backend.b.a.<init>(Unknown Source)

[00:20:14 WARN]:        at com.jakub.jpremium.backend.Backend.c(Unknown Source)

[00:20:14 WARN]:        at com.jakub.jpremium.backend.Backend.onEnable(Unknown Source)

[00:20:14 WARN]:        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:321)

[00:20:14 WARN]:        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:332)

[00:20:14 WARN]:        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:393)

[00:20:14 WARN]:        at org.bukkit.craftbukkit.v1_8_R3.CraftServer.loadPlugin(CraftServer.java:353)

[00:20:14 WARN]:        at org.bukkit.craftbukkit.v1_8_R3.CraftServer.enablePlugins(CraftServer.java:312)

[00:20:14 WARN]:        at net.minecraft.server.v1_8_R3.MinecraftServer.s(MinecraftServer.java:402)

[00:20:14 WARN]:        at net.minecraft.server.v1_8_R3.MinecraftServer.k(MinecraftServer.java:366)

[00:20:14 WARN]:        at net.minecraft.server.v1_8_R3.MinecraftServer.a(MinecraftServer.java:328)

[00:20:14 WARN]:        at net.minecraft.server.v1_8_R3.DedicatedServer.init(DedicatedServer.java:290)

[00:20:14 WARN]:        at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:559)

[00:20:14 WARN]:        at java.base/java.lang.Thread.run(Thread.java:833)