---- Minecraft Crash Report ----
// This doesn't make any sense!

Time: 8/7/16 7:16 PM
Description: Exception in server tick loop

cpw.mods.fml.common.LoaderException: java.lang.NoClassDefFoundError: Llumien/resourceloader/loader/NormalResourceLoader;
at cpw.mods.fml.common.LoadController.transition(LoadController.java:163)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:544)
at cpw.mods.fml.server.FMLServerHandler.beginServerLoading(FMLServerHandler.java:87)
at cpw.mods.fml.common.FMLCommonHandler.onServerStart(FMLCommonHandler.java:314)
at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:117)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:387)
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685)
Caused by: java.lang.NoClassDefFoundError: Llumien/resourceloader/loader/NormalResourceLoader;
at java.lang.Class.getDeclaredFields0(Native Method)
at java.lang.Class.privateGetDeclaredFields(Unknown Source)
at java.lang.Class.getDeclaredField(Unknown Source)
at cpw.mods.fml.common.FMLModContainer.parseSimpleFieldAnnotation(FMLModContainer.java:404)
at cpw.mods.fml.common.FMLModContainer.processFieldAnnotations(FMLModContainer.java:358)
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:513)
at sun.reflect.GeneratedMethodAccessor5.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:212)
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:190)
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:119)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:513)
... 5 more
Caused by: java.lang.ClassNotFoundException: lumien.resourceloader.loader.NormalResourceLoader
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 32 more
Caused by: java.lang.NoClassDefFoundError: net/minecraft/client/resources/IResourcePack
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:182)
... 34 more
Caused by: java.lang.ClassNotFoundException: net.minecraft.client.resources.IResourcePack
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 38 more
Caused by: java.lang.NullPointerException
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:182)
... 40 more

Me: so idk what this means but any help is great.

First of all, it would be awesome if you wouldn't post a giant wall of text and instead put the crash report on pastebin.com and post the link to it here.
To your actual problem: This has nothing to do with BigReactors and is caused by you trying to use a client side only mod on a dedicated server. Removing the mod ResourceLoader from the server should fix this.