[18:53:34] [Server thread/ERROR] [Sponge]: The Scheduler tried to run the task gwm_crates-S-18 owned by Plugin{id=gwm_crates, name=GWMCrates, version=1.121, description=Universal crates plugin for your server!, authors=[GWM], source=/opt/msm/servers/rtest/mods/GWMCrates.jar}, but an error occured.
java.lang.NoSuchMethodError: org.spongepowered.api.item.inventory.ItemStack.empty()Lorg/spongepowered/api/item/inventory/ItemStack;
        at ua.gwm.sponge_plugin.crates.preview.previews.FirstGuiPreview$DropChangeRunnable.run(FirstGuiPreview.java:111) ~[FirstGuiPreview$DropChangeRunnable.class:?]
        at org.spongepowered.api.scheduler.Task$Builder.lambda$execute$0(Task.java:139) ~[Task$Builder.class:1.10.2-2281-5.2.0-BETA-2371]
        at org.spongepowered.common.scheduler.SchedulerBase.lambda$startTask$0(SchedulerBase.java:183) ~[SchedulerBase.class:1.10.2-2281-5.2.0-BETA-2371]
        at org.spongepowered.common.scheduler.SyncScheduler.executeTaskRunnable(SyncScheduler.java:81) ~[SyncScheduler.class:1.10.2-2281-5.2.0-BETA-2371]
        at org.spongepowered.common.scheduler.SchedulerBase.startTask(SchedulerBase.java:179) ~[SchedulerBase.class:1.10.2-2281-5.2.0-BETA-2371]
        at org.spongepowered.common.scheduler.SchedulerBase.processTask(SchedulerBase.java:165) ~[SchedulerBase.class:1.10.2-2281-5.2.0-BETA-2371]
        at java.util.concurrent.ConcurrentHashMap$ValuesView.forEach(ConcurrentHashMap.java:4707) [?:1.8.0_72]
        at org.spongepowered.common.scheduler.SchedulerBase.runTick(SchedulerBase.java:108) [SchedulerBase.class:1.10.2-2281-5.2.0-BETA-2371]
        at org.spongepowered.common.scheduler.SyncScheduler.tick(SyncScheduler.java:51) [SyncScheduler.class:1.10.2-2281-5.2.0-BETA-2371]
        at org.spongepowered.common.scheduler.SpongeScheduler.tickSyncScheduler(SpongeScheduler.java:191) [SpongeScheduler.class:1.10.2-2281-5.2.0-BETA-2371]
        at org.spongepowered.mod.SpongeMod.onTick(SpongeMod.java:271) [SpongeMod.class:1.10.2-2281-5.2.0-BETA-2371]
        at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_11_SpongeMod_onTick_ServerTickEvent.invoke(.dynamic) [?:?]
        at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90) [ASMEventHandler.class:?]
        at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:635) [EventBus.class:?]
        at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:591) [EventBus.class:?]
        at net.minecraftforge.fml.common.FMLCommonHandler.onPreServerTick(FMLCommonHandler.java:274) [FMLCommonHandler.class:?]
        at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:602) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:471) [MinecraftServer.class:?]
        at java.lang.Thread.run(Thread.java:745) [?:1.8.0_72]