[20:18:45] [Server thread/ERROR] [Sponge]: Could not pass FMLInitializationEvent to Plugin{id=MinecraftGui, name=Minecraft Gui Server, version=2.0}
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
        at java.lang.String.substring(String.java:1967) ~[?:1.8.0_66]
        at io.github.minecraftgui.views.sponge.Sponge.onInitializationEvent(Sponge.java:68) ~[Sponge.class:?]
        at org.spongepowered.common.event.listener.GameInitializationEventListener_Sponge_onInitializationEvent17.handle(Unknown Source) ~[?:?]
        at org.spongepowered.common.event.RegisteredListener.handle(RegisteredListener.java:86) ~[RegisteredListener.class:1.8.9-1694-3.1.0-BETA-1094]
        at org.spongepowered.mod.event.SpongeModEventManager.post(SpongeModEventManager.java:233) [SpongeModEventManager.class:1.8.9-1694-3.1.0-BETA-1094]
        at org.spongepowered.mod.event.SpongeModEventManager.post(SpongeModEventManager.java:277) [SpongeModEventManager.class:1.8.9-1694-3.1.0-BETA-1094]
        at org.spongepowered.mod.SpongeMod.onStateEvent(SpongeMod.java:185) [SpongeMod.class:1.8.9-1694-3.1.0-BETA-1094]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_66]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_66]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_66]
        at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_66]
        at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) [minecraft_server.1.8.9.jar:?]
        at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) [minecraft_server.1.8.9.jar:?]
        at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) [minecraft_server.1.8.9.jar:?]
        at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) [minecraft_server.1.8.9.jar:?]
        at com.google.common.eventbus.EventBus.post(EventBus.java:275) [minecraft_server.1.8.9.jar:?]
        at net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:211) [LoadController.class:?]
        at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:189) [LoadController.class:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_66]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_66]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_66]
        at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_66]
        at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) [minecraft_server.1.8.9.jar:?]
        at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) [minecraft_server.1.8.9.jar:?]
        at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) [minecraft_server.1.8.9.jar:?]
        at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) [minecraft_server.1.8.9.jar:?]
        at com.google.common.eventbus.EventBus.post(EventBus.java:275) [minecraft_server.1.8.9.jar:?]
        at net.minecraftforge.fml.common.LoadController.onPost(LoadController.java:53) [LoadController.class:?]
        at net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:118) [LoadController.class:?]
        at net.minecraftforge.fml.common.Loader.initializeMods(Loader.java:737) [Loader.class:?]
        at net.minecraftforge.fml.server.FMLServerHandler.finishServerLoading(FMLServerHandler.java:97) [FMLServerHandler.class:?]
        at net.minecraftforge.fml.common.FMLCommonHandler.onServerStarted(FMLCommonHandler.java:324) [FMLCommonHandler.class:?]
        at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:205) [ko.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:441) [MinecraftServer.class:?]
        at java.lang.Thread.run(Thread.java:745) [?:1.8.0_66]