Bukkit

[14:20:37 ERROR]: [AdvancedSpawners] Failed to check and correct invalid configurated levels.
java.lang.NullPointerException: null
at me.greenadine.advancedspawners.AdvancedSpawners.checkLevels(AdvancedSpawners.java:203) ~[?:?]
at me.greenadine.advancedspawners.AdvancedSpawners.onEnable(AdvancedSpawners.java:108) ~[?:?]
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:263) ~[patched_1.14.4.jar:git-Paper-172]
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:338) ~[patched_1.14.4.jar:git-Paper-172]
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:420) ~[patched_1.14.4.jar:git-Paper-172]
at org.bukkit.craftbukkit.v1_14_R1.CraftServer.enablePlugin(CraftServer.java:467) ~[patched_1.14.4.jar:git-Paper-172]
at org.bukkit.craftbukkit.v1_14_R1.CraftServer.enablePlugins(CraftServer.java:381) ~[patched_1.14.4.jar:git-Paper-172]
at net.minecraft.server.v1_14_R1.MinecraftServer.a(MinecraftServer.java:474) ~[patched_1.14.4.jar:git-Paper-172]
at net.minecraft.server.v1_14_R1.DedicatedServer.init(DedicatedServer.java:290) ~[patched_1.14.4.jar:git-Paper-172]
at net.minecraft.server.v1_14_R1.MinecraftServer.run(MinecraftServer.java:869) ~[patched_1.14.4.jar:git-Paper-172]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_221]