SEVERE: Unable to Launch

[Phantomstrk]

Getting this message when using the FTB launcher and launching the monster modpack. I've tried all i can think of and it still won't work.

Strange thing is that i need to run it as "administrator" in order to even get it to work. Running windows 8.1. Other modpacks seem to work fine, just can't get this one going.

The FTB Launcher has found the following Java versions installed:
The FTB Launcher has found the following Java versions installed:
Java Path: C:\Program Files\Java\jre7\bin\javaw.exe
Setting MinMemory to 256
Setting MaxMemory to 4096
Defaulting PermSize to 256m
Jan 08, 2014 10:00:43 PM net.minecraft.launchwrapper.LogWrapper log
INFO: Loading tweak class name cpw.mods.fml.common.launcher.FMLTweaker
Jan 08, 2014 10:00:43 PM net.minecraft.launchwrapper.LogWrapper log
SEVERE: Unable to launch
java.lang.ClassNotFoundException: cpw.mods.fml.common.launcher.FMLTweaker
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:102)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:94)
at net.minecraft.launchwrapper.Launch.main(Launch.java:27)

 

[Phantomstrk]

so no one has seen this error before ??? hard to believe