Launcher Won't Run Modpack: Class FMLTweaker not found?

[iconmaster]

Launcher Version: 269

Operating System: Windows 7

Java Version: Java 7

Antivirus Program: None

Description of Problem:

When I hit 'Play' in my already-downloaded modpack (http://www.technicpack.net/modpack/details/iconuspack-beta.98944), it displays the launching bar at 0% for a frame, but then reverts back to idle without doing anything. Only in the error logs does it state the error. It could be that I packaged my modpack wrong; it isn't exactly obvious how it should go.

Error Messages:

N/A

Error Log:

2013/10/14 09:03:35 [iNFO] ------------------------------------------

2013/10/14 09:03:35 [iNFO] Technic Launcher is starting....

2013/10/14 09:03:35 [iNFO] Launcher Build: 269

2013/10/14 09:03:35 [iNFO] ------------ Startup Parameters ------------

2013/10/14 09:03:35 [iNFO] --------- End of Startup Parameters ---------

2013/10/14 09:03:35 [iNFO] Loaded face

2013/10/14 09:03:36 [iNFO] Starting download of http://skins.technicpack.net/helm/iconmaster5326/100, with 3 tries remaining

2013/10/14 09:03:37 [iNFO] Launcher took: 2317ms to start

2013/10/14 09:03:43 [WARNING] File version.json not found in C:\Users\iconmaster\AppData\Roaming\.technic\iconuspack-beta\bin\modpack.jar

2013/10/14 09:03:43 [iNFO] Running C:\Program Files (x86)\Java\jdk1.7.0_25\jre\bin\javaw.exe -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1024m -XX:MaxPermSize=128m -Djava.library.path=C:\Users\iconmaster\AppData\Roaming\.technic\iconuspack-beta\bin\natives -Dminecraft.applet.TargetDirectory=C:\Users\iconmaster\AppData\Roaming\.technic\iconuspack-beta -cp C:\Users\iconmaster\AppData\Roaming\.technic\cache\net\minecraft\launchwrapper\1.3\launchwrapper-1.3.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\org\ow2\asm\asm-all\4.1\asm-all-4.1.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\org\scala-lang\scala-library\2.10.2\scala-library-2.10.2.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\org\scala-lang\scala-compiler\2.10.2\scala-compiler-2.10.2.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\net\sf\jopt-simple\jopt-simple\4.5\jopt-simple-4.5.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\lzma\lzma\0.0.1\lzma-0.0.1.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\com\paulscode\codecjorbis\20101023\codecjorbis-20101023.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\com\paulscode\codecwav\20101023\codecwav-20101023.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\com\paulscode\libraryjavasound\20101123\libraryjavasound-20101123.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\com\paulscode\librarylwjglopenal\20100824\librarylwjglopenal-20100824.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\com\paulscode\soundsystem\20120107\soundsystem-20120107.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\org\lwjgl\lwjgl\lwjgl\2.9.0\lwjgl-2.9.0.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\org\lwjgl\lwjgl\lwjgl_util\2.9.0\lwjgl_util-2.9.0.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\argo\argo\2.25_fixed\argo-2.25_fixed.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\org\bouncycastle\bcprov-jdk15on\1.47\bcprov-jdk15on-1.47.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\com\google\guava\guava\14.0\guava-14.0.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\org\apache\commons\commons-lang3\3.1\commons-lang3-3.1.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\commons-io\commons-io\2.4\commons-io-2.4.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\net\java\jinput\jinput\2.0.5\jinput-2.0.5.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\net\java\jutils\jutils\1.0.0\jutils-1.0.0.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\com\google\code\gson\gson\2.2.2\gson-2.2.2.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\org\lwjgl\lwjgl\lwjgl\2.9.0\lwjgl-2.9.0.jar;C:\Users\iconmaster\AppData\Roaming\.technic\cache\org\lwjgl\lwjgl\lwjgl_util\2.9.0\lwjgl_util-2.9.0.jar;C:\Users\iconmaster\AppData\Roaming\.technic\iconuspack-beta\bin\modpack.jar;C:\Users\iconmaster\AppData\Roaming\.technic\iconuspack-beta\bin\minecraft.jar net.minecraft.launchwrapper.Launch --username iconmaster5326 --session token:67813da0fedf4a9cb43c7ebe40c42530:c02448bf07924516b690e0cabcdeb690 --version 1.6.2-Forge9.10.1.871 --gameDir C:\Users\iconmaster\AppData\Roaming\.technic\iconuspack-beta --assetsDir C:\Users\iconmaster\AppData\Roaming\.technic\assets --tweakClass cpw.mods.fml.common.launcher.FMLTweaker

2013/10/14 09:03:43 [iNFO]  Oct 14, 2013 9:03:43 AM net.minecraft.launchwrapper.LogWrapper log

2013/10/14 09:03:43 [iNFO]  INFO: Using tweak class name cpw.mods.fml.common.launcher.FMLTweaker

2013/10/14 09:03:43 [iNFO]  Oct 14, 2013 9:03:43 AM net.minecraft.launchwrapper.LogWrapper log

2013/10/14 09:03:43 [iNFO]  SEVERE: Unable to launch

2013/10/14 09:03:43 [iNFO]  java.lang.ClassNotFoundException: cpw.mods.fml.common.launcher.FMLTweaker

2013/10/14 09:03:43 [iNFO]  	at java.net.URLClassLoader$1.run(URLClassLoader.java:366)

2013/10/14 09:03:43 [iNFO]  	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)

2013/10/14 09:03:43 [iNFO]  	at java.security.AccessController.doPrivileged(Native Method)

2013/10/14 09:03:43 [iNFO]  	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)

2013/10/14 09:03:43 [iNFO]  	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)

2013/10/14 09:03:43 [iNFO]  	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)

2013/10/14 09:03:43 [iNFO]  	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

2013/10/14 09:03:43 [iNFO]  	at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:99)

2013/10/14 09:03:43 [iNFO]  	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)

2013/10/14 09:03:43 [iNFO]  	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

2013/10/14 09:03:43 [iNFO]  	at java.lang.Class.forName0(Native Method)

2013/10/14 09:03:43 [iNFO]  	at java.lang.Class.forName(Class.java:270)

2013/10/14 09:03:43 [iNFO]  	at net.minecraft.launchwrapper.Launch.launch(Launch.java:49)

2013/10/14 09:03:43 [iNFO]  	at net.minecraft.launchwrapper.Launch.main(Launch.java:18)

2013/10/14 09:03:43 [iNFO]

[iconmaster]

It WAS my mis-packaging of the modpack that caused the crash. Sorry for wasting your time!