I get this when I play with Magic Launcher 1.1.5: *** MagicMinecraftLauncher 1.1.5 *** LCP: C:\Users\ryann_000\Desktop\Stuff\SinglePlayerCommands-MC1.5.2_V4.8.zip;C:\Users\ryann_000\Desktop\Stuff\mccapes_1_5_2_20130501_2122.zip;C:\Users\ryann_000\Desktop\Mo Bends 1.5.2.zip;C:\Users\ryann_000\Desktop\Sonic Ether's Unbelievable Shaders 1.5.2.zip;C:\Users\ryann_000\AppData\Roaming\.minecraft\versions\1.5.2\1.5.2.jar;C:\Users\ryann_000\AppData\Roaming\.minecraft\libraries\net\minecraft\launchwrapper\1.2\launchwrapper-1.2.jar;C:\Users\ryann_000\AppData\Roaming\.minecraft\libraries\net\sf\jopt-simple\jopt-simple\4.5\jopt-simple-4.5.jar;C:\Users\ryann_000\AppData\Roaming\.minecraft\libraries\org\ow2\asm\asm-all\4.1\asm-all-4.1.jar;C:\Users\ryann_000\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl\2.9.0\lwjgl-2.9.0.jar;C:\Users\ryann_000\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl_util\2.9.0\lwjgl_util-2.9.0.jar;C:\Users\ryann_000\AppData\Roaming\.minecraft\libraries\net\java\jinput\jinput\2.0.5\jinput-2.0.5.jar;C:\Users\ryann_000\AppData\Roaming\.minecraft\libraries\net\java\jutils\jutils\1.0.0\jutils-1.0.0.jar;C:\Users\ryann_000\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl-platform\2.9.0\lwjgl-platform-2.9.0-natives-windows.jar;C:\Users\ryann_000\AppData\Roaming\.minecraft\libraries\net\java\jinput\jinput-platform\2.0.5\jinput-platform-2.0.5-natives-windows.jar InactiveExtMods: Explosives+ v3.4.jar;KenshiroMod_1.5.2.zip;LittleBlocks-Universal-v2.1.0.0.zip;SlimevoidLib-Universal-v2.0.1.1.zip;WorldEdit.jar InactiveCoreMods: More bows 1.5.2_2 Forge (2).jar MainClass: net.minecraft.launchwrapper.Launch java.lang.ClassNotFoundException: net.minecraft.launchwrapper.Launch 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 java.lang.ClassLoader.loadClass(Unknown Source) at magic.launcher.Launcher.main(Unknown Source) HALP!
Have you updated your mods such as optifine? This happened to me when I didnt update my mods, so i would recommend updating your mods if you have not done so. Also this should be in the help and support section not off topic.