[13:44:57] [Server thread/ERROR] [Sponge]: Could not pass InteractItemEvent$Primary$MainHand$Impl to Plugin{id=gwm_crates, name=GWMCrates, version=1.121, description=Universal crates plugin for your server!, authors=[GWM], source=/opt/msm/servers/rtest/mods/GWMCrates.jar}
java.lang.BootstrapMethodError: java.lang.NoSuchMethodError: org.spongepowered.api.item.inventory.ItemStack.empty()Lorg/spongepowered/api/item/inventory/ItemStack;
        at ua.gwm.sponge_plugin.crates.drop.Drop.getDropItem(Drop.java:57) ~[Drop.class:?]
        at ua.gwm.sponge_plugin.crates.preview.previews.FirstGuiPreview.preview(FirstGuiPreview.java:80) ~[FirstGuiPreview.class:?]
        at ua.gwm.sponge_plugin.crates.listener.ItemCaseListener.startItemCasePreview(ItemCaseListener.java:79) ~[ItemCaseListener.class:?]
        at org.spongepowered.common.event.listener.MainHandListener_ItemCaseListener_startItemCasePreview37.handle(Unknown Source) ~[?:?]
        at org.spongepowered.common.event.RegisteredListener.handle(RegisteredListener.java:95) ~[RegisteredListener.class:1.10.2-2281-5.2.0-BETA-2401]
        at org.spongepowered.mod.event.SpongeModEventManager.post(SpongeModEventManager.java:313) [SpongeModEventManager.class:1.10.2-2281-5.2.0-BETA-2401]
        at org.spongepowered.mod.event.SpongeModEventManager.post(SpongeModEventManager.java:342) [SpongeModEventManager.class:1.10.2-2281-5.2.0-BETA-2401]
        at org.spongepowered.mod.event.SpongeModEventManager.post(SpongeModEventManager.java:326) [SpongeModEventManager.class:1.10.2-2281-5.2.0-BETA-2401]
        at org.spongepowered.common.SpongeImpl.postEvent(SpongeImpl.java:143) [SpongeImpl.class:1.10.2-2281-5.2.0-BETA-2401]
        at org.spongepowered.common.event.SpongeCommonEventFactory.callInteractItemEventPrimary(SpongeCommonEventFactory.java:424) [SpongeCommonEventFactory.class:1.10.2-2281-5.2.0-BETA-2401]
        at net.minecraft.server.MinecraftServer.handler$onServerTickEnd$zhn000(MinecraftServer.java:3785) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:658) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:471) [MinecraftServer.class:?]
        at java.lang.Thread.run(Thread.java:745) [?:1.8.0_72]
Caused by: java.lang.NoSuchMethodError: org.spongepowered.api.item.inventory.ItemStack.empty()Lorg/spongepowered/api/item/inventory/ItemStack;
        at java.lang.invoke.MethodHandleNatives.resolve(Native Method) ~[?:1.8.0_72]
        at java.lang.invoke.MemberName$Factory.resolve(MemberName.java:962) ~[?:1.8.0_72]
        at java.lang.invoke.MemberName$Factory.resolveOrFail(MemberName.java:987) ~[?:1.8.0_72]
        at java.lang.invoke.MethodHandles$Lookup.resolveOrFail(MethodHandles.java:1390) ~[?:1.8.0_72]
        at java.lang.invoke.MethodHandles$Lookup.linkMethodHandleConstant(MethodHandles.java:1746) ~[?:1.8.0_72]
        at java.lang.invoke.MethodHandleNatives.linkMethodHandleConstant(MethodHandleNatives.java:477) ~[?:1.8.0_72]
        ... 14 more