IllegalAccessError

Running code Schematic schematic = DataTranslators.SCHEMATIC.translate(schematicData);
(SchematicData is a DataContainer)

The error I’m getting is

[Server thread/ERROR] [Sponge]: Could not pass FMLInitializationEvent to Plugin{id=spongyisland, name=Spongy Island, version=0.3.2, description=A skyblock plugin for sponge, source=D:\Minecraft Plugins\Sponge Plugins\DeluxeSkyBlock\bin} java.lang.IllegalAccessError: tried to access field net.minecraft.tileentity.TileEntity.REGISTRY from class org.spongepowered.common.data.persistence.SchematicTranslator at org.spongepowered.common.data.persistence.SchematicTranslator.translate(SchematicTranslator.java:185) ~[SchematicTranslator.class:?] at org.spongepowered.common.data.persistence.SchematicTranslator.translate(SchematicTranslator.java:1) ~[SchematicTranslator.class:?] at io.github.kernegal.spongyisland.utils.IslandManager.<init>(IslandManager.java:109) ~[IslandManager.class:?] at io.github.kernegal.spongyisland.SpongyIsland.init(SpongyIsland.java:284) ~[SpongyIsland.class:?] at org.spongepowered.common.event.listener.GameInitializationEventListener_SpongyIsland_init1.handle(Unknown Source) ~[?:?] at org.spongepowered.common.event.RegisteredListener.handle(RegisteredListener.java:95) ~[RegisteredListener.class:?] at org.spongepowered.mod.event.SpongeModEventManager.post(SpongeModEventManager.java:301) [SpongeModEventManager.class:?] at org.spongepowered.mod.event.SpongeModEventManager.post(SpongeModEventManager.java:330) [SpongeModEventManager.class:?] at org.spongepowered.mod.SpongeMod.onStateEvent(SpongeMod.java:201) [SpongeMod.class:?] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_74] at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_74] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_74] at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_74] at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) [guava-17.0.jar:?] at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) [guava-17.0.jar:?] at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) [guava-17.0.jar:?] at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) [guava-17.0.jar:?] at com.google.common.eventbus.EventBus.post(EventBus.java:275) [guava-17.0.jar:?] at net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:243) [LoadController.class:?] at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:221) [LoadController.class:?] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_74] at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_74] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_74] at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_74] at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) [guava-17.0.jar:?] at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) [guava-17.0.jar:?] at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) [guava-17.0.jar:?] at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) [guava-17.0.jar:?] at com.google.common.eventbus.EventBus.post(EventBus.java:275) [guava-17.0.jar:?] at net.minecraftforge.fml.common.LoadController.redirect$onPost$zzd000(LoadController.java:53) [LoadController.class:?] at net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:145) [LoadController.class:?] at net.minecraftforge.fml.common.Loader.initializeMods(Loader.java:797) [Loader.class:?] at net.minecraftforge.fml.server.FMLServerHandler.finishServerLoading(FMLServerHandler.java:108) [FMLServerHandler.class:?] at net.minecraftforge.fml.common.FMLCommonHandler.onServerStarted(FMLCommonHandler.java:334) [FMLCommonHandler.class:?] at net.minecraft.server.dedicated.DedicatedServer.init(DedicatedServer.java:218) [DedicatedServer.class:?] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:507) [MinecraftServer.class:?] at java.lang.Thread.run(Unknown Source) [?:1.8.0_74]

What version of SpongeForge are you running?

I’m running the latest 6.0 build.

Could you post the full fml-server-latest.log? I think something may have broken earlier in the startup.
Also make sure the forge version matches the version spongeforge expects