NoClassDefFoundError on a new Pixelmon Server? [closed]

I'm trying to make a Pixelmon server, I followed the instructions of this video but it won't start:

Its a Cauldron server. Any idea what is going wrong? I am using:

• Pixelmon: 3.4,
• Minecraft: 1.7.10 ,
• Cauldron: cauldron-1.7.10-1.1207.01.198
• OS: Windows 8.1 (amd64) version 6.3
• Java: 1.7.0_71

Thanks in advance!

---- Minecraft Crash Report ----
// Oh - I know what I did wrong!

Time: 2/21/15 12:33 PM
Description: Exception in server tick loop

cpw.mods.fml.common.LoaderException: java.lang.NoClassDefFoundError: net/minecraftforge/event/world/BlockEvent$PlaceEvent
    at cpw.mods.fml.common.LoadController.transition(LoadController.java:162)
    at cpw.mods.fml.common.Loader.preinitializeMods(Loader.java:515)
    at cpw.mods.fml.server.FMLServerHandler.beginServerLoading(FMLServerHandler.java:88)
    at cpw.mods.fml.common.FMLCommonHandler.onServerStart(FMLCommonHandler.java:317)
    at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:170)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:620)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NoClassDefFoundError: net/minecraftforge/event/world/BlockEvent$PlaceEvent
    at com.pixelmonmod.pixelmon.config.PixelmonItemsBlocks.load(PixelmonItemsBlocks.java:28)
    at com.pixelmonmod.pixelmon.config.PixelmonItems.load(PixelmonItems.java:221)
    at com.pixelmonmod.pixelmon.config.PixelmonConfig.loadConfig(PixelmonConfig.java:160)
    at com.pixelmonmod.pixelmon.Pixelmon.preInit(Pixelmon.java:105)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at cpw.mods.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:513)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74)
    at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47)
    at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322)
    at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304)
    at com.google.common.eventbus.EventBus.post(EventBus.java:275)
    at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:208)
    at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:187)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74)
    at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47)
    at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322)
    at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304)
    at com.google.common.eventbus.EventBus.post(EventBus.java:275)
    at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:118)
    at cpw.mods.fml.common.Loader.preinitializeMods(Loader.java:513)
    ... 5 more
Caused by: java.lang.ClassNotFoundException: net.minecraftforge.event.world.BlockEvent$PlaceEvent
    at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:188)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    ... 36 more
Caused by: java.lang.NullPointerException


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- System Details --
Details:
    Minecraft Version: 1.7.10
    Operating System: Windows 8.1 (amd64) version 6.3
    Java Version: 1.7.0_71, Oracle Corporation
    Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
    Memory: 135834656 bytes (129 MB) / 372768768 bytes (355 MB) up to 2796552192 bytes (2667 MB)
    JVM Flags: 1 total; -Xmx3000M
    AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
    IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
    FML: MCP v9.05 FML v7.10.25.1207 Minecraft Forge 10.13.0.1207 4 mods loaded, 4 mods active
    mcp{9.05} [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized
    FML{7.10.25.1207} [Forge Mod Loader] (cauldronserver.jar) Unloaded->Constructed->Pre-initialized
    Forge{10.13.0.1207} [Minecraft Forge] (cauldronserver.jar) Unloaded->Constructed->Pre-initialized
    pixelmon{3.4.0} [Pixelmon] (Pixelmon-1.7.10-3.4.0-universal.jar) Unloaded->Constructed->Errored
    Profiler Position: N/A (disabled)
    Is Modded: Definitely; Server brand changed to 'cauldron,craftbukkit,mcpc,fml,forge'
    Type: Dedicated Server (map_server.txt)