Upon placing a beacon this happens. I've tried with an empty hand too. This corrupts the world it's in. This happens with just this mod installed. Using forge 2811.

[23:11:19] [Server thread/FATAL] [VanillaFix]: Error executing task java.util.concurrent.ExecutionException: kotlin.KotlinNullPointerException at java.util.concurrent.FutureTask.report(Unknown Source) ~[?:1.8.0_191] at java.util.concurrent.FutureTask.get(Unknown Source) ~[?:1.8.0_191] at net.minecraft.util.Util.runTask(SourceFile:531) [h.class:?] at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:723) [MinecraftServer.class:?] at net.minecraft.server.dedicated.DedicatedServer.updateTimeLightAndEntities(DedicatedServer.java:397) [nz.class:?] at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:668) [MinecraftServer.class:?] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526) [MinecraftServer.class:?] at java.lang.Thread.run(Unknown Source) [?:1.8.0_191] Caused by: kotlin.KotlinNullPointerException at de.mineformers.vanillaimmersion.tileentity.BeaconLogic.writeToNBT(BeaconLogic.kt:103) ~[BeaconLogic.class:?] at net.minecraft.tileentity.TileEntityBeacon.getUpdateTag(TileEntityBeacon.java:269) ~[avh.class:?] at net.minecraft.tileentity.TileEntityBeacon.getUpdatePacket(TileEntityBeacon.java:264) ~[avh.class:?] at de.mineformers.vanillaimmersion.tileentity.TileEntityExtensions.sync(extensions.kt:16) ~[TileEntityExtensions.class:?] at de.mineformers.vanillaimmersion.tileentity.BeaconLogic.setField(BeaconLogic.kt:131) ~[BeaconLogic.class:?] at de.mineformers.vanillaimmersion.tileentity.BeaconLogic.setPrimaryEffect(BeaconLogic.kt:23) ~[BeaconLogic.class:?] at de.mineformers.vanillaimmersion.block.Beacon.onBlockActivated(Beacon.kt:73) ~[Beacon.class:?] at net.minecraft.server.management.PlayerInteractionManager.processRightClickBlock(PlayerInteractionManager.java:449) ~[or.class:?] at net.minecraft.network.NetHandlerPlayServer.processTryUseItemOnBlock(NetHandlerPlayServer.java:741) ~[pa.class:?] at net.minecraft.network.play.client.CPacketPlayerTryUseItemOnBlock.processPacket(SourceFile:55) ~[ma.class:?] at net.minecraft.network.play.client.CPacketPlayerTryUseItemOnBlock.processPacket(SourceFile:11) ~[ma.class:?] at net.minecraft.network.PacketThreadUtil$1.run(SourceFile:13) ~[hv$1.class:?] at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:1.8.0_191] at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:1.8.0_191] at net.minecraft.util.Util.runTask(SourceFile:529) ~[h.class:?] ... 5 more