My modded minecraft server just gets stuck here

25.03 11:29:25 [Server] Server thread/INFO [FML]: Applying holder lookups
25.03 11:29:25 [Server] Server thread/INFO [FML]: Holder lookups applied
25.03 11:29:26 [Server] Server thread/INFO [Chisel]: Loading items...
25.03 11:29:26 [Server] Server thread/INFO [Chisel]: Skipping feature arcaneStone as its required mod thaumcraft was missing.
25.03 11:29:26 [Server] Server thread/INFO [Chisel]: 74 Feature's items loaded.
25.03 11:29:27 [Server] Server thread/ERROR [FML]: Exception caught during firing event net.minecraftforge.event.RegistryEvent$Register@43c1c720:
25.03 11:29:27 [Server] INFO java.lang.NoClassDefFoundError: net/minecraft/client/multiplayer/WorldClient
25.03 11:29:27 [Server] INFO at net.arsenalnetwork.arcanearteries.EventSubscriber.onRegisterItemsEvent(EventSubscriber.java:46) ~[EventSubscriber.class:?]
25.03 11:29:27 [Server] INFO at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_518_EventSubscriber_onRegisterItemsEvent_Register.invoke(.dynamic) ~[?:?]
25.03 11:29:27 [Server] INFO at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90) ~[ASMEventHandler.class:?]
25.03 11:29:27 [Server] INFO at net.minecraftforge.fml.common.eventhandler.EventBus$1.invoke(EventBus.java:144) ~[EventBus$1.class:?]
25.03 11:29:27 [Server] INFO at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:182) [EventBus.class:?]
25.03 11:29:27 [Server] INFO at net.minecraftforge.registries.GameData.fireRegistryEvents(GameData.java:850) [GameData.class:?]
25.03 11:29:27 [Server] INFO at net.minecraftforge.fml.common.Loader.preinitializeMods(Loader.java:630) [Loader.class:?]
25.03 11:29:27 [Server] INFO at net.minecraftforge.fml.server.FMLServerHandler.beginServerLoading(FMLServerHandler.java:99) [FMLServerHandler.class:?]
25.03 11:29:27 [Server] INFO at net.minecraftforge.fml.common.FMLCommonHandler.onServerStart(FMLCommonHandler.java:333) [FMLCommonHandler.class:?]
25.03 11:29:27 [Server] INFO at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:125) [nz.class:?]
25.03 11:29:27 [Server] INFO at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:486) [MinecraftServer.class:?]
25.03 11:29:27 [Server] INFO at java.lang.Thread.run(Thread.java:748) [?:1.8.0_212]
25.03 11:29:27 [Server] INFO Caused by: java.lang.ClassNotFoundException: net.minecraft.client.multiplayer.WorldClient
25.03 11:29:27 [Server] INFO at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191) ~[launchwrapper-1.12.jar:?]
25.03 11:29:27 [Server] INFO at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_212]
25.03 11:29:27 [Server] INFO at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_212]
25.03 11:29:27 [Server] INFO ... 12 more
25.03 11:29:27 [Server] INFO Caused by: net.minecraftforge.fml.common.asm.ASMTransformerWrapper$TransformerException: Exception in class transformer net.minecraftforge.fml.common.asm.transformers.SideTransformer@325bb9a6 from coremod FMLCorePlugin
25.03 11:29:27 [Server] INFO at net.minecraftforge.fml.common.asm.ASMTransformerWrapper$TransformerWrapper.transform(ASMTransformerWrapper.java:260) ~[forge1122.jar:?]
25.03 11:29:27 [Server] INFO at net.minecraft.launchwrapper.LaunchClassLoader.runTransformers(LaunchClassLoader.java:279) ~[launchwrapper-1.12.jar:?]
25.03 11:29:27 [Server] INFO at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:176) ~[launchwrapper-1.12.jar:?]
25.03 11:29:27 [Server] INFO at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_212]
25.03 11:29:27 [Server] INFO at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_212]
25.03 11:29:27 [Server] INFO ... 12 more
25.03 11:29:27 [Server] INFO Caused by: java.lang.RuntimeException: Attempted to load class bsb for invalid side SERVER
25.03 11:29:27 [Server] INFO at net.minecraftforge.fml.common.asm.transformers.SideTransformer.transform(SideTransformer.java:62) ~[forge1122.jar:?]
25.03 11:29:27 [Server] INFO at net.minecraftforge.fml.common.asm.ASMTransformerWrapper$TransformerWrapper.transform(ASMTransformerWrapper.java:256) ~[forge1122.jar:?]
25.03 11:29:27 [Server] INFO at net.minecraft.launchwrapper.LaunchClassLoader.runTransformers(LaunchClassLoader.java:279) ~[launchwrapper-1.12.jar:?]