plugin exporting IPX

org.bukkit.plugin.InvalidPluginException: java.lang.ExceptionInInitializerError
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:135) ~[spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:327) ~[spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:248) [spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        at org.bukkit.craftbukkit.v1_13_R1.CraftServer.loadPlugins(CraftServer.java:315) [spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        at net.minecraft.server.v1_13_R1.DedicatedServer.init(DedicatedServer.java:213) [spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        at net.minecraft.server.v1_13_R1.MinecraftServer.run(MinecraftServer.java:686) [spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        at java.lang.Thread.run(Unknown Source) [?:?]
Caused by: java.lang.ExceptionInInitializerError
        at com.videosambo.motimaa.Taivas.Main.<init>(Main.java:13) ~[?:?]
        at jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:?]
        at jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) ~[?:?]
        at jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) ~[?:?]
        at java.lang.reflect.Constructor.newInstance(Unknown Source) ~[?:?]
        at java.lang.Class.newInstance(Unknown Source) ~[?:?]
        at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:90) ~[spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:131) ~[spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        ... 6 more
Caused by: java.lang.IllegalArgumentException: Plugin already initialized!
        at org.bukkit.plugin.java.PluginClassLoader.initialize(PluginClassLoader.java:185) ~[spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        at org.bukkit.plugin.java.JavaPlugin.<init>(JavaPlugin.java:60) ~[spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        at com.videosambo.motimaa.Taivas.Main.<init>(Main.java:11) ~[?:?]
        at com.videosambo.motimaa.Taivas.ConfigManager.<clinit>(ConfigManager.java:14) ~[?:?]
        at com.videosambo.motimaa.Taivas.Main.<init>(Main.java:13) ~[?:?]
        at jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:?]
        at jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) ~[?:?]
        at jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) ~[?:?]
        at java.lang.reflect.Constructor.newInstance(Unknown Source) ~[?:?]
        at java.lang.Class.newInstance(Unknown Source) ~[?:?]
        at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:90) ~[spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:131) ~[spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        ... 6 more
Caused by: java.lang.IllegalStateException: Initial initialization
        at org.bukkit.plugin.java.PluginClassLoader.initialize(PluginClassLoader.java:188) ~[spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        at org.bukkit.plugin.java.JavaPlugin.<init>(JavaPlugin.java:60) ~[spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        at com.videosambo.motimaa.Taivas.Main.<init>(Main.java:11) ~[?:?]
        at jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:?]
        at jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) ~[?:?]
        at jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) ~[?:?]
        at java.lang.reflect.Constructor.newInstance(Unknown Source) ~[?:?]
        at java.lang.Class.newInstance(Unknown Source) ~[?:?]
        at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:90) ~[spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:131) ~[spigot-1.13.jar:git-Spigot-fe3ab0d-ec86574]
        ... 6 more