error: EntityInjector

[mluizaa00]

EntityInjector setAi method is having a exception:

[14:42:19 ERROR]: Could not pass event InventoryClickEvent to RankUPCore v1.0.0
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) ~[patched.jar:git-PaperSpigot-"4c7641d"]
        at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:78) ~[patched.jar:git-PaperSpigot-"4c7641d"]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[patched.jar:git-PaperSpigot-"4c7641d"]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:517) [patched.jar:git-PaperSpigot-"4c7641d"]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:502) [patched.jar:git-PaperSpigot-"4c7641d"]
        at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:1657) [patched.jar:git-PaperSpigot-"4c7641d"]
        at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:31) [patched.jar:git-PaperSpigot-"4c7641d"]
        at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:9) [patched.jar:git-PaperSpigot-"4c7641d"]
        at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [patched.jar:git-PaperSpigot-"4c7641d"]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_282]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_282]
        at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [patched.jar:git-PaperSpigot-"4c7641d"]
        at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:774) [patched.jar:git-PaperSpigot-"4c7641d"]
        at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:378) [patched.jar:git-PaperSpigot-"4c7641d"]
        at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:713) [patched.jar:git-PaperSpigot-"4c7641d"]
        at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:616) [patched.jar:git-PaperSpigot-"4c7641d"]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_282]
Caused by: java.lang.NullPointerException
        at com.celeste.library.spigot.util.EntityInjector.set(EntityInjector.java:67) ~[?:?]
        at com.celeste.library.spigot.util.EntityInjector.setInt(EntityInjector.java:91) ~[?:?]
        at com.celeste.library.spigot.util.EntityInjector.setAi(EntityInjector.java:57) ~[?:?]
        at net.hylex.spawners.controllers.EntityController.setAI(EntityController.java:98) ~[?:?]
        at net.hylex.spawners.controllers.EntityController.register(EntityController.java:60) ~[?:?]
        at net.hylex.spawners.views.menus.SpawnerInfoMenu.lambda$onRender$1(SpawnerInfoMenu.java:59) ~[?:?]
        at com.celeste.library.spigot.model.menu.MenuHolder.handleClick(MenuHolder.java:219) ~[?:?]
        at com.celeste.library.spigot.view.listener.MenuListener.onInventoryClick(MenuListener.java:35) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_282]