[FML]: An Entity type net.shadowmage.ancientwarfare.npc.entity.NpcCombat has thrown an exception trying to write state. It will not persist. Report this to the mod author
net.minecraft.util.ReportedException: Saving entity NBT
at net.minecraft.entity.Entity.func_189511_e(Entity.java:1769) ~[vg.class:?]
at net.minecraft.entity.Entity.func_70039_c(Entity.java:1651) ~[vg.class:?]
at net.minecraft.world.chunk.storage.AnvilChunkLoader.func_75820_a(AnvilChunkLoader.java:361) [aye.class:?]
at net.minecraft.world.chunk.storage.AnvilChunkLoader.func_75816_a(AnvilChunkLoader.java:173) [aye.class:?]
at net.minecraft.world.gen.ChunkProviderServer.func_73242_b(ChunkProviderServer.java:202) [on.class:?]
at net.minecraft.world.gen.ChunkProviderServer.func_186027_a(ChunkProviderServer.java:230) [on.class:?]
at net.minecraft.world.WorldServer.func_73044_a(WorldServer.java:1006) [oo.class:?]
at org.spongepowered.common.world.WorldManager.saveWorld(WorldManager.java:532) [WorldManager.class:1.12.2-2611-7.1.0-BETA-2925]
at net.minecraft.server.MinecraftServer.func_71267_a(MinecraftServer.java:3947) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.constant$getSaveTickInterval$zjf000(MinecraftServer.java:3900) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:685) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:524) [MinecraftServer.class:?]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_161]
Caused by: java.lang.NullPointerException
at net.shadowmage.ancientwarfare.npc.npc_command.NpcCommand$Command.writeToNBT(NpcCommand.java:119) ~[NpcCommand$Command.class:?]
at net.shadowmage.ancientwarfare.npc.entity.NpcPlayerOwned.func_70014_b(NpcPlayerOwned.java:349) ~[NpcPlayerOwned.class:?]
at net.shadowmage.ancientwarfare.npc.entity.NpcCombat.func_70014_b(NpcCombat.java:187) ~[NpcCombat.class:?]
at net.minecraft.entity.Entity.func_189511_e(Entity.java:1740) ~[vg.class:?]
... 12 more
[20:35:24] [Server thread/INFO] [nucleus]: mosa ran the command: /sethome
[20:35:35] [Server thread/FATAL]: Error executing task
java.util.concurrent.ExecutionException: java.lang.ClassCastException: org.spongepowered.common.item.inventory.lens.impl.slots.SlotLensImpl cannot be cast to org.spongepowered.common.item.inventory.lens.slots.CraftingOutputSlotLens
at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[?:1.8.0_161]
at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[?:1.8.0_161]
at net.minecraft.util.Util.func_181617_a(SourceFile:47) [h.class:?]
at org.spongepowered.common.SpongeImplHooks.onUtilRunTask(SpongeImplHooks.java:276) [SpongeImplHooks.class:1.12.2-2611-7.1.0-BETA-2925]
at net.minecraft.server.MinecraftServer.redirect$onRun$zjf000(MinecraftServer.java:4003) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:721) [MinecraftServer.class:?]
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:396) [nz.class:?]
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:666) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:524) [MinecraftServer.class:?]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_161]
Caused by: java.lang.ClassCastException: org.spongepowered.common.item.inventory.lens.impl.slots.SlotLensImpl cannot be cast to org.spongepowered.common.item.inventory.lens.slots.CraftingOutputSlotLens
at org.spongepowered.common.item.inventory.lens.impl.comp.CraftingInventoryLensImpl.(CraftingInventoryLensImpl.java:55) ~[CraftingInventoryLensImpl.class:1.12.2-2611-7.1.0-BETA-2925]
at org.spongepowered.common.item.inventory.lens.impl.comp.CraftingInventoryLensImpl.(CraftingInventoryLensImpl.java:49) ~[CraftingInventoryLensImpl.class:1.12.2-2611-7.1.0-BETA-2925]
at org.spongepowered.common.item.inventory.util.ContainerUtil.generateLens(ContainerUtil.java:338) ~[ContainerUtil.class:1.12.2-2611-7.1.0-BETA-2925]
at org.spongepowered.common.item.inventory.util.ContainerUtil.getLens(ContainerUtil.java:233) ~[ContainerUtil.class:1.12.2-2611-7.1.0-BETA-2925]
at net.minecraft.inventory.Container.spongeInit(Container.java:1013) ~[afr.class:?]
at net.minecraft.inventory.Container.detectAndSendChanges(Container.java:1066) ~[afr.class:?]
at net.minecraft.inventory.Container.func_75142_b(Container.java:1061) ~[afr.class:?]
at net.minecraft.inventory.Container.func_75132_a(Container.java:1048) ~[afr.class:?]
at net.minecraftforge.fml.common.network.internal.FMLNetworkHandler.openGui(FMLNetworkHandler.java:100) ~[FMLNetworkHandler.class:?]
at net.shadowmage.ancientwarfare.core.network.NetworkHandler.openGui(NetworkHandler.java:192) ~[NetworkHandler.class:?]
at net.shadowmage.ancientwarfare.core.network.NetworkHandler.openGui(NetworkHandler.java:184) ~[NetworkHandler.class:?]
at net.shadowmage.ancientwarfare.core.block.BlockEngineeringStation.func_180639_a(BlockEngineeringStation.java:81) ~[BlockEngineeringStation.class:?]
at net.minecraft.server.management.PlayerInteractionManager.func_187251_a(PlayerInteractionManager.java:1249) ~[or.class:?]
at net.minecraft.network.NetHandlerPlayServer.redirect$onProcessRightClickBlock$zik000(NetHandlerPlayServer.java:2377) ~[pa.class:?]
at net.minecraft.network.NetHandlerPlayServer.func_184337_a(NetHandlerPlayServer.java:739) ~[pa.class:?]
at net.minecraft.network.play.client.CPacketPlayerTryUseItemOnBlock.func_148833_a(SourceFile:55) ~[ma.class:?]
at net.minecraft.network.play.client.CPacketPlayerTryUseItemOnBlock.func_148833_a(SourceFile:11) ~[ma.class:?]
at org.spongepowered.common.network.PacketUtil.onProcessPacket(PacketUtil.java:149) ~[PacketUtil.class:1.12.2-2611-7.1.0-BETA-2925]
at net.minecraft.network.PacketThreadUtil$1.redirect$onProcessPacket$zla000(SourceFile:539) ~[hv$1.class:?]
at net.minecraft.network.PacketThreadUtil$1.run(SourceFile:13) ~[hv$1.class:?]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[?:1.8.0_161]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[?:1.8.0_161]
at net.minecraft.util.Util.func_181617_a(SourceFile:46) ~[h.class:?]
... 7 more

And then the server crash. IS the sponge problem or the mod's problem ?

I have just uploaded new version on curseforge which should fix this crash.