Crash de mon serveur minecraft

Bonjour, depuis quelques temps j'ai changé d'hebergeur mais aussi de mods et mon serveur crash alors que mon minecraft non (alors qu'ils ont les mêmes mods)
voici le crash-report :

[22:08:44] [Server thread/ERROR]: Encountered an unexpected exception
cpw.mods.fml.common.LoaderException: java.lang.NoClassDefFoundError: net/minecraft/client/multiplayer/WorldClient
at cpw.mods.fml.common.LoadController.transition(LoadController.java:163) ~[LoadController.class:?]
at cpw.mods.fml.common.Loader.loadMods(Loader.java:544) ~[Loader.class:?]
at cpw.mods.fml.server.FMLServerHandler.beginServerLoading(FMLServerHandler.java:87) ~[FMLServerHandler.class:?]
at cpw.mods.fml.common.FMLCommonHandler.onServerStart(FMLCommonHandler.java:314) ~[FMLCommonHandler.class:?]
at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:117) ~[lt.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:387) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685) [li.class:?]
Caused by: java.lang.NoClassDefFoundError: net/minecraft/client/multiplayer/WorldClient
at modid.imsm.core.IMSM.<clinit>(IMSM.java:195) ~[IMSM.class:?]
at java.lang.Class.forName0(Native Method) ~[?:1.8.0_72]
at java.lang.Class.forName(Class.java:348) ~[?:1.8.0_72]
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:440) ~[FMLModContainer.class:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_72]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_72]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_72]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_72]
at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) ~[guava-17.0.jar:?]
at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.post(EventBus.java:275) ~[guava-17.0.jar:?]
at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:212) ~[LoadController.class:?]
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:190) ~[LoadController.class:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_72]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_72]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_72]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_72]
at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) ~[guava-17.0.jar:?]
at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.post(EventBus.java:275) ~[guava-17.0.jar:?]
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:119) ~[LoadController.class:?]
at cpw.mods.fml.common.Loader.loadMods(Loader.java:513) ~[Loader.class:?]
... 5 more
Caused by: java.lang.ClassNotFoundException: net.minecraft.client.multiplayer.WorldClient
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191) ~[launchwrapper-1.12.jar:?]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_72]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_72]
at modid.imsm.core.IMSM.<clinit>(IMSM.java:195) ~[IMSM.class:?]
at java.lang.Class.forName0(Native Method) ~[?:1.8.0_72]
at java.lang.Class.forName(Class.java:348) ~[?:1.8.0_72]
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:440) ~[FMLModContainer.class:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_72]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_72]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_72]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_72]
at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) ~[guava-17.0.jar:?]
at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.post(EventBus.java:275) ~[guava-17.0.jar:?]
at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:212) ~[LoadController.class:?]
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:190) ~[LoadController.class:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_72]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_72]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_72]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_72]
at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) ~[guava-17.0.jar:?]
at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.post(EventBus.java:275) ~[guava-17.0.jar:?]
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:119) ~[LoadController.class:?]
at cpw.mods.fml.common.Loader.loadMods(Loader.java:513) ~[Loader.class:?]
... 5 more
Caused by: java.lang.RuntimeException: Attempted to load class bjf for invalid side SERVER
at cpw.mods.fml.common.asm.transformers.SideTransformer.transform(SideTransformer.java:50) ~[forge-1.7.10-10.13.4.1614-1.7.10-universal.jar:?]
at net.minecraft.launchwrapper.LaunchClassLoader.runTransformers(LaunchClassLoader.java:279) ~[launchwrapper-1.12.jar:?]
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:176) ~[launchwrapper-1.12.jar:?]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_72]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_72]
at modid.imsm.core.IMSM.<clinit>(IMSM.java:195) ~[IMSM.class:?]
at java.lang.Class.forName0(Native Method) ~[?:1.8.0_72]
at java.lang.Class.forName(Class.java:348) ~[?:1.8.0_72]
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:440) ~[FMLModContainer.class:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_72]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_72]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_72]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_72]
at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) ~[guava-17.0.jar:?]
at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.post(EventBus.java:275) ~[guava-17.0.jar:?]
at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:212) ~[LoadController.class:?]
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:190) ~[LoadController.class:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_72]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_72]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_72]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_72]
at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74) ~[guava-17.0.jar:?]
at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304) ~[guava-17.0.jar:?]
at com.google.common.eventbus.EventBus.post(EventBus.java:275) ~[guava-17.0.jar:?]
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:119) ~[LoadController.class:?]
at cpw.mods.fml.common.Loader.loadMods(Loader.java:513) ~[Loader.class:?]
... 5 more

Merci d'avance à ceux qui pourront m'aider