>.... [18:49:55 ERROR]: Could not pass event MythicMobDeathEvent to MMOCore v1.4.7
java.lang.IllegalArgumentException: Player must be online
at org.apache.commons.lang.Validate.notNull(Validate.java:192) ~[patched_1.15.2.jar:git-Paper-387]
at net.mmogroup.mmolib.api.player.MMOPlayerData.getPlayer(MMOPlayerData.java:79) ~[?:?]
at net.Indyuce.mmocore.api.player.PlayerData.getPlayer(PlayerData.java:166) ~[?:?]
at net.Indyuce.mmocore.comp.mythicmobs.load.KillMythicMobObjective$KillMobProgress.a(KillMythicMobObjective.java:41) ~[?:?]
at com.destroystokyo.paper.event.executor.asm.generated.GeneratedEventExecutor843.execute(Unknown Source) ~[?:?]
at org.bukkit.plugin.EventExecutor.lambda$create$1(EventExecutor.java:69) ~[patched_1.15.2.jar:git-Paper-387]
at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:80) ~[patched_1.15.2.jar:git-Paper-387]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[patched_1.15.2.jar:git-Paper-387]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:607) ~[patched_1.15.2.jar:git-Paper-387]
at io.lumine.xikage.mythicmobs.adapters.bukkit.BukkitSkillTriggers.onDeathTrigger(BukkitSkillTriggers.java:464) ~[?:?]
at com.destroystokyo.paper.event.executor.asm.generated.GeneratedEventExecutor479.execute(Unknown Source) ~[?:?]
at org.bukkit.plugin.EventExecutor.lambda$create$1(EventExecutor.java:69) ~[patched_1.15.2.jar:git-Paper-387]
at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:80) ~[patched_1.15.2.jar:git-Paper-387]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[patched_1.15.2.jar:git-Paper-387]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:607) ~[patched_1.15.2.jar:git-Paper-387]
at org.bukkit.craftbukkit.v1_15_R1.event.CraftEventFactory.callEntityDeathEvent(CraftEventFactory.java:767) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.EntityLiving.d(EntityLiving.java:1380) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.EntityLiving.die(EntityLiving.java:1308) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.EntityLiving.damageEntity(EntityLiving.java:1152) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.EntityHuman.attack(EntityHuman.java:1113) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.EntityPlayer.attack(EntityPlayer.java:1753) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.PlayerConnection.a(PlayerConnection.java:2105) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.PacketPlayInUseEntity.a(PacketPlayInUseEntity.java:51) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.PacketPlayInUseEntity.a(PacketPlayInUseEntity.java:6) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.PlayerConnectionUtils.lambda$ensureMainThread$1(PlayerConnectionUtils.java:23) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.TickTask.run(SourceFile:18) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.executeTask(IAsyncTaskHandler.java:136) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.executeNext(IAsyncTaskHandler.java:109) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.MinecraftServer.ba(MinecraftServer.java:1106) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.MinecraftServer.executeNext(MinecraftServer.java:1099) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.awaitTasks(IAsyncTaskHandler.java:119) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.MinecraftServer.sleepForTick(MinecraftServer.java:1060) ~[patched_1.15.2.jar:git-Paper-387]
at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:975) ~[patched_1.15.2.jar:git-Paper-387]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_262]