java.lang.NoClassDefFoundError: org/spongepowered/api/service/permission/context/ContextCalculator
        at java.lang.Class.forName0(Native Method) ~[?:1.8.0_65]
        at java.lang.Class.forName(Class.java:348) ~[?:1.8.0_65]
        at org.spongepowered.mod.plugin.SpongeModPluginContainer.constructMod(SpongeModPluginContainer.java:94) ~[Sponge.jar:1.8-1577-2.1-DEV-992]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_65]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_65]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_65]
        at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_65]
        at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) ~[minecraft_server.1.8.jar:?]
        at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) ~[minecraft_server.1.8.jar:?]
        at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) ~[minecraft_server.1.8.jar:?]
        at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) ~[minecraft_server.1.8.jar:?]
        at com.google.common.eventbus.EventBus.post(EventBus.java:275) ~[minecraft_server.1.8.jar:?]
        at net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:212) ~[LoadController.class:?]
        at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:190) ~[LoadController.class:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_65]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_65]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_65]
        at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_65]
        at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) ~[minecraft_server.1.8.jar:?]
        at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) ~[minecraft_server.1.8.jar:?]
        at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) ~[minecraft_server.1.8.jar:?]
        at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) ~[minecraft_server.1.8.jar:?]
        at com.google.common.eventbus.EventBus.post(EventBus.java:275) ~[minecraft_server.1.8.jar:?]
        at net.minecraftforge.fml.common.LoadController.onPost(LoadController.java:54) ~[LoadController.class:?]
        at net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:119) ~[LoadController.class:?]
        at net.minecraftforge.fml.common.Loader.loadMods(Loader.java:507) ~[Loader.class:?]
        at net.minecraftforge.fml.server.FMLServerHandler.beginServerLoading(FMLServerHandler.java:87) ~[FMLServerHandler.class:?]
        at net.minecraftforge.fml.common.FMLCommonHandler.onServerStart(FMLCommonHandler.java:355) ~[FMLCommonHandler.class:?]
        at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:117) ~[po.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:438) [MinecraftServer.class:?]
        at java.lang.Thread.run(Thread.java:745) [?:1.8.0_65]
Caused by: java.lang.ClassNotFoundException: org.spongepowered.api.service.permission.context.ContextCalculator
        at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191) ~[launchwrapper-1.12.jar:?]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_65]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_65]
        ... 31 more
Caused by: java.lang.NullPointerException
        at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:182) ~[launchwrapper-1.12.jar:?]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_65]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_65]
        ... 31 more