pixelmon battling npc trainers crashes server but not battle players

[elanvital4321]

java.lang.NoClassDefFoundError: org/spongepowered/api/command/CommandCallable
at com.pixelmonmod.pixelmon.battles.controller.participants.PlayerParticipant.getPrizeMoneyMultiplier(PlayerParticipant.java:674)
at com.pixelmonmod.pixelmon.entities.npcs.NPCTrainer.loseBattle(NPCTrainer.java:606)
at com.pixelmonmod.pixelmon.battles.controller.participants.TrainerParticipant.endBattle(TrainerParticipant.java:170)
at com.pixelmonmod.pixelmon.battles.controller.BattleControllerBase.endBattle(BattleControllerBase.java:833)
at com.pixelmonmod.pixelmon.battles.controller.BattleControllerBase.endBattle(BattleControllerBase.java:725)
at com.pixelmonmod.pixelmon.battles.controller.BattleControllerBase.endBattle(BattleControllerBase.java:843)
at com.pixelmonmod.pixelmon.battles.controller.BattleControllerBase.checkDefeated(BattleControllerBase.java:1168)
at com.pixelmonmod.pixelmon.battles.controller.BattleControllerBase.checkPokemon(BattleControllerBase.java:1111)
at com.pixelmonmod.pixelmon.battles.controller.BattleControllerBase.update(BattleControllerBase.java:389)
at com.pixelmonmod.pixelmon.battles.BattleRegistry.updateBattles(BattleRegistry.java:242)
at com.pixelmonmod.pixelmon.battles.BattleTickHandler.tickStart(BattleTickHandler.java:17)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_192_BattleTickHandler_tickStart_WorldTickEvent.invoke(.dynamic)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:190)
at net.minecraftforge.fml.common.FMLCommonHandler.onPostWorldTick(FMLCommonHandler.java:276)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:998)
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:461)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:865)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:737)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.ClassNotFoundException: org.spongepowered.api.command.CommandCallable
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191)
at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
at java.lang.ClassLoader.loadClass(ClassLoader.java:351)