stack trace

[22:28:15] [Server thread/ERROR] [FML]: Caught exception from theoneprobe
java.lang.IllegalAccessError: no such constructor: mcjty.theoneprobe.apiimpl.elements.ElementEntity.<init>(ByteBuf)void/newInvokeSpecial
	at java.lang.invoke.MethodHandleNatives.linkMethodHandleConstant(MethodHandleNatives.java:483) ~[?:1.8.0_51]
	at mcjty.theoneprobe.apiimpl.TheOneProbeImp.registerElements(TheOneProbeImp.java:36) ~[TheOneProbe-1.9.4-1.0.3-12.jar:?]
	at mcjty.theoneprobe.proxy.CommonProxy.preInit(CommonProxy.java:28) ~[TheOneProbe-1.9.4-1.0.3-12.jar:?]
	at mcjty.theoneprobe.proxy.ServerProxy.preInit(ServerProxy.java:11) ~[TheOneProbe-1.9.4-1.0.3-12.jar:?]
	at mcjty.theoneprobe.TheOneProbe.preInit(TheOneProbe.java:63) ~[TheOneProbe-1.9.4-1.0.3-12.jar:?]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_51]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_51]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_51]
	at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_51]
	at net.minecraftforge.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:563) ~[forgeSrc-1.9.4-12.17.0.1910-1.9.4.jar:?]
	at sun.reflect.GeneratedMethodAccessor10.invoke(Unknown Source) ~[?:?]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_51]
	at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_51]
	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 net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:228) ~[forgeSrc-1.9.4-12.17.0.1910-1.9.4.jar:?]
	at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:206) ~[forgeSrc-1.9.4-12.17.0.1910-1.9.4.jar:?]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_51]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_51]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_51]
	at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_51]
	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 net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:135) [LoadController.class:?]
	at net.minecraftforge.fml.common.Loader.preinitializeMods(Loader.java:584) [Loader.class:?]
	at net.minecraftforge.fml.server.FMLServerHandler.beginServerLoading(FMLServerHandler.java:93) [FMLServerHandler.class:?]
	at net.minecraftforge.fml.common.FMLCommonHandler.onServerStart(FMLCommonHandler.java:320) [FMLCommonHandler.class:?]
	at net.minecraft.server.dedicated.DedicatedServer.startServer(DedicatedServer.java:121) [DedicatedServer.class:?]
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:494) [MinecraftServer.class:?]
	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_51]
Caused by: java.lang.NoClassDefFoundError: net/minecraft/client/multiplayer/WorldClient
	at java.lang.invoke.MethodHandleNatives.resolve(Native Method) ~[?:1.8.0_51]
	at java.lang.invoke.MemberName$Factory.resolve(MemberName.java:962) ~[?:1.8.0_51]
	at java.lang.invoke.MemberName$Factory.resolveOrFail(MemberName.java:987) ~[?:1.8.0_51]
	at java.lang.invoke.MethodHandles$Lookup.resolveOrFail(MethodHandles.java:1390) ~[?:1.8.0_51]
	at java.lang.invoke.MethodHandles$Lookup.linkMethodHandleConstant(MethodHandles.java:1746) ~[?:1.8.0_51]
	at java.lang.invoke.MethodHandleNatives.linkMethodHandleConstant(MethodHandleNatives.java:477) ~[?:1.8.0_51]
	... 35 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_51]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_51]
	at java.lang.invoke.MethodHandleNatives.resolve(Native Method) ~[?:1.8.0_51]
	at java.lang.invoke.MemberName$Factory.resolve(MemberName.java:962) ~[?:1.8.0_51]
	at java.lang.invoke.MemberName$Factory.resolveOrFail(MemberName.java:987) ~[?:1.8.0_51]
	at java.lang.invoke.MethodHandles$Lookup.resolveOrFail(MethodHandles.java:1390) ~[?:1.8.0_51]
	at java.lang.invoke.MethodHandles$Lookup.linkMethodHandleConstant(MethodHandles.java:1746) ~[?:1.8.0_51]
	at java.lang.invoke.MethodHandleNatives.linkMethodHandleConstant(MethodHandleNatives.java:477) ~[?:1.8.0_51]
	... 35 more
Caused by: net.minecraftforge.fml.common.asm.ASMTransformerWrapper$TransformerException: Exception in class transformer net.minecraftforge.fml.common.asm.transformers.SideTransformer@1950e8a6 from coremod FMLCorePlugin
	at net.minecraftforge.fml.common.asm.ASMTransformerWrapper$TransformerWrapper.transform(ASMTransformerWrapper.java:234) ~[forgeSrc-1.9.4-12.17.0.1910-1.9.4.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_51]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_51]
	at java.lang.invoke.MethodHandleNatives.resolve(Native Method) ~[?:1.8.0_51]
	at java.lang.invoke.MemberName$Factory.resolve(MemberName.java:962) ~[?:1.8.0_51]
	at java.lang.invoke.MemberName$Factory.resolveOrFail(MemberName.java:987) ~[?:1.8.0_51]
	at java.lang.invoke.MethodHandles$Lookup.resolveOrFail(MethodHandles.java:1390) ~[?:1.8.0_51]
	at java.lang.invoke.MethodHandles$Lookup.linkMethodHandleConstant(MethodHandles.java:1746) ~[?:1.8.0_51]
	at java.lang.invoke.MethodHandleNatives.linkMethodHandleConstant(MethodHandleNatives.java:477) ~[?:1.8.0_51]
	... 35 more
Caused by: java.lang.RuntimeException: Attempted to load class net/minecraft/client/multiplayer/WorldClient for invalid side SERVER
	at net.minecraftforge.fml.common.asm.transformers.SideTransformer.transform(SideTransformer.java:49) ~[forgeSrc-1.9.4-12.17.0.1910-1.9.4.jar:?]
	at net.minecraftforge.fml.common.asm.ASMTransformerWrapper$TransformerWrapper.transform(ASMTransformerWrapper.java:230) ~[forgeSrc-1.9.4-12.17.0.1910-1.9.4.jar:?]
	at net.minecraft.launchwrapper.LaunchClassLoader.runTransformers(LaunchClassLoader.java:279) ~[launchwrapper-1.12.jar:?]
	at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:176) ~[launchwrapper-1.12.jar:?]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_51]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_51]
	at java.lang.invoke.MethodHandleNatives.resolve(Native Method) ~[?:1.8.0_51]
	at java.lang.invoke.MemberName$Factory.resolve(MemberName.java:962) ~[?:1.8.0_51]
	at java.lang.invoke.MemberName$Factory.resolveOrFail(MemberName.java:987) ~[?:1.8.0_51]
	at java.lang.invoke.MethodHandles$Lookup.resolveOrFail(MethodHandles.java:1390) ~[?:1.8.0_51]
	at java.lang.invoke.MethodHandles$Lookup.linkMethodHandleConstant(MethodHandles.java:1746) ~[?:1.8.0_51]
	at java.lang.invoke.MethodHandleNatives.linkMethodHandleConstant(MethodHandleNatives.java:477) ~[?:1.8.0_51]
	... 35 more