Can't launch after downloading mod pack

[WLPAzrael]

I wanted to try and download the mod pack, BusinessElite, but after it started to download it got stuck at loading "1% modpack.jar..." and won't start the client itself. The process repeats if I delete the mod and try again.

Additionally, the java console next to the launcher says (from beginning because I'm not sure where the issue is)

Loaded face

Starting download of http://skins.technicpack.net/helm/KOADarchangel/100, with 3 tries remaining

Pack: businesselite Image Download Worker Calculated MD5: 60b25451c6934e1693159710751193a5 Required MD5: ec96fde004824ab6a4e3bb5bf8f55ee1

Starting download of ' alt='' class='ipsImage' >, with 3 tries remaining

Pack: businesselite Image Download Worker Calculated MD5: 60b25451c6934e1693159710751193a5 Required MD5: ec96fde004824ab6a4e3bb5bf8f55ee1

Starting download of ' alt='' class='ipsImage' >, with 3 tries remaining

Starting download of http://mirror.technicpack.net/Technic/lib/macosx_natives.jar, with 3 tries remaining

Expected MD5: 1BEC35FE0F76E93A46A26D56EDD952AB Calculated MD5: 1bec35fe0f76e93a46a26d56edd952ab

Starting download of http://www.thfieldservices.com/businesselite/Business3.2.4.zip, with 3 tries remaining

org.spoutcraft.launcher.exceptions.UnknownMinecraftException

at org.spoutcraft.launcher.launch.MinecraftLauncher.getMinecraftApplet(MinecraftLauncher.java:99)

at org.spoutcraft.launcher.GameLauncher.runGame(GameLauncher.java:139)

at org.spoutcraft.launcher.GameUpdater.runGame(GameUpdater.java:136)

at org.spoutcraft.launcher.skin.components.LoginFrame.onEvent(LoginFrame.java:312)

at org.spoutcraft.launcher.skin.components.LoginWorker.doInBackground(LoginWorker.java:103)

at org.jdesktop.swingworker.SwingWorker$1.call(Unknown Source)

at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)

at java.util.concurrent.FutureTask.run(FutureTask.java:138)

at org.jdesktop.swingworker.SwingWorker.run(Unknown Source)

at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)

at java.lang.Thread.run(Thread.java:680)

Caused by: java.lang.NoClassDefFoundError: lg

at java.lang.ClassLoader.defineClass1(Native Method)

at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)

at java.lang.ClassLoader.defineClass(ClassLoader.java:615)

at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)

at org.spoutcraft.launcher.launch.MinecraftClassLoader.findClassInjar(MinecraftClassLoader.java:169)

at org.spoutcraft.launcher.launch.MinecraftClassLoader.findClass(MinecraftClassLoader.java:143)

at java.lang.ClassLoader.loadClass(ClassLoader.java:306)

at java.lang.ClassLoader.loadClass(ClassLoader.java:247)

at org.spoutcraft.launcher.launch.MinecraftLauncher.setMinecraftDirectory(MinecraftLauncher.java:110)

at org.spoutcraft.launcher.launch.MinecraftLauncher.getMinecraftApplet(MinecraftLauncher.java:86)

... 11 more

Caused by: java.lang.ClassNotFoundException: lg

at java.net.URLClassLoader$1.run(URLClassLoader.java:202)

at java.security.AccessController.doPrivileged(Native Method)

at java.net.URLClassLoader.findClass(URLClassLoader.java:190)

at org.spoutcraft.launcher.launch.MinecraftClassLoader.findClass(MinecraftClassLoader.java:149)

at java.lang.ClassLoader.loadClass(ClassLoader.java:306)

at java.lang.ClassLoader.loadClass(ClassLoader.java:247)

... 21 more"

and the screen looks like this: