Please Help! [11:04:46] [Server thread/WARN]: [MobHunting] Task #57 for MobHunting v7.0.7

I do not what i am missing or what i did wrong here but can someone help me? This is my error message. It generated after a player logs in.


[11:04:46] [Server thread/WARN]: [MobHunting] Task #57 for MobHunting v7.0.7 generated an exception
java.lang.NullPointerException: null
at one.lindegaard.MobHunting.achievements.AchievementManager$3.onCompleted(AchievementManager.java:664) ~[?:?]
at one.lindegaard.MobHunting.achievements.AchievementManager$3.onCompleted(AchievementManager.java:602) ~[?:?]
at one.lindegaard.MobHunting.storage.DataStoreManager$CallbackCaller.run(DataStoreManager.java:341) ~[?:?]
at org.bukkit.craftbukkit.v1_15_R1.scheduler.CraftTask.run(CraftTask.java:77) ~[bukkit.jar:git-Bukkit-8160e29]
at org.bukkit.craftbukkit.v1_15_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:393) [bukkit.jar:git-Bukkit-8160e29]
at net.minecraft.server.v1_15_R1.MinecraftServer.b(MinecraftServer.java:985) [bukkit.jar:git-Bukkit-8160e29]
at net.minecraft.server.v1_15_R1.DedicatedServer.b(DedicatedServer.java:386) [bukkit.jar:git-Bukkit-8160e29]
at net.minecraft.server.v1_15_R1.MinecraftServer.a(MinecraftServer.java:940) [bukkit.jar:git-Bukkit-8160e29]
at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:789) [bukkit.jar:git-Bukkit-8160e29]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_241]

 

ok thank you

https://pastebin.com/s1trrM1z

EDIT by Moderator: merged posts, please use the edit button instead of double posting.