[17:43:58 ERROR]: Could not pass event PlayerSwapHandItemsEvent to Creative v1.0
org.bukkit.event.EventException: null
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot-1.12.2.jar:git-Spigot-3d850ec-809c399]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot-1.12.2.jar:git-Spigot-3d850ec-809c399]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:500) [spigot-1.12.2.jar:git-Spigot-3d850ec-809c399]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:485) [spigot-1.12.2.jar:git-Spigot-3d850ec-809c399]
        at net.minecraft.server.v1_12_R1.PlayerConnection.a(PlayerConnection.java:815) [spigot-1.12.2.jar:git-Spigot-3d850ec-809c399]
        at net.minecraft.server.v1_12_R1.PacketPlayInBlockDig.a(SourceFile:40) [spigot-1.12.2.jar:git-Spigot-3d850ec-809c399]
        at net.minecraft.server.v1_12_R1.PacketPlayInBlockDig.a(SourceFile:10) [spigot-1.12.2.jar:git-Spigot-3d850ec-809c399]
        at net.minecraft.server.v1_12_R1.PlayerConnectionUtils$1.run(SourceFile:13) [spigot-1.12.2.jar:git-Spigot-3d850ec-809c399]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_171]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_171]
        at net.minecraft.server.v1_12_R1.SystemUtils.a(SourceFile:46) [spigot-1.12.2.jar:git-Spigot-3d850ec-809c399]
        at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:748) [spigot-1.12.2.jar:git-Spigot-3d850ec-809c399]
        at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:406) [spigot-1.12.2.jar:git-Spigot-3d850ec-809c399]
        at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:679) [spigot-1.12.2.jar:git-Spigot-3d850ec-809c399]
        at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:577) [spigot-1.12.2.jar:git-Spigot-3d850ec-809c399]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_171]
Caused by: java.lang.NullPointerException
        at creative.Main.getStacksByName(Main.java:24) ~[?:?]
        at creative.Main.s(Main.java:44) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_171]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_171]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_171]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_171]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) ~[spigot-1.12.2.jar:git-Spigot-3d850ec-809c399]
        ... 15 more