java.lang.NoClassDefFoundError: scala/actors/threadpool/Arrays
	at com.windanesz.ancientspellcraft.spell.SummonQuicksand.onBlockHit(SummonQuicksand.java:63)
	at electroblob.wizardry.spell.SpellRay.shootSpell(SpellRay.java:283)
	at electroblob.wizardry.spell.SpellRay.cast(SpellRay.java:168)
	at electroblob.wizardry.item.ItemWand.cast(ItemWand.java:478)
	at electroblob.wizardry.item.ItemWand.onUsingTick(ItemWand.java:442)
	at net.minecraft.entity.EntityLivingBase.func_184608_ct(EntityLivingBase.java:2678)
	at net.minecraft.entity.EntityLivingBase.func_70071_h_(EntityLivingBase.java:2097)
	at net.minecraft.entity.player.EntityPlayer.func_70071_h_(EntityPlayer.java:234)
	at net.minecraft.entity.player.EntityPlayerMP.func_71127_g(EntityPlayerMP.java:382)
	at net.minecraft.network.NetHandlerPlayServer.func_73660_a(NetHandlerPlayServer.java:173)
	at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher$1.func_73660_a(NetworkDispatcher.java:209)
	at net.minecraft.network.NetworkManager.func_74428_b(NetworkManager.java:285)
	at net.minecraft.network.NetworkSystem.func_151269_c(NetworkSystem.java:180)
	at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:790)
	at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:668)
	at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:185)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: scala.actors.threadpool.Arrays
	at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 18 more
Caused by: java.lang.NullPointerException