Minecraft Forums

Whenever i try to launch the newest launcher on snapshot 13w23a, under the version selection page the only version available is (default). I can log in fine, and when i try to launch the process works fine until the lines where it says "---- YOU CAN CLOSE THIS LAUNCHER IF THE GAME STARTED OK ----". Then, instead of the game starting, i get more lines saying
Client> Exception in thread "main" java.lang.NoClassDefFoundError: net/minecraft/client/main/Main
Client> Caused by: java.lang.ClassNotFoundException: net.minecraft.client.main.Main
Client> at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
Client> at java.security.AccessController.doPrivileged(Native Method)
Client> at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
Client> at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
Client> at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
Client> at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
Game ended with bad state (exit code 1)
Deleting /Users/cole~/Library/Application Support/minecraft/versions/13w23b/13w23b-natives-1370883805060915000

I have tried redownloading and restarting my modem to no avail. Please help?

Try again. There was a bug in the latest version of the launcher and it's been fixed. Your launcher should auto update itself and work.

This is caused by the launcher launching with the wrong main class

Quick Fix:
- Go to AppData/.minecraft
- Open the Version folder
- Open the affected version
- Open the .json file in a text editor
- change the following line (near bottom):
- "mainClass": "net/minecraft/client/main/Main"
to
- "mainClass": "net.minecraft.client.Minecraft"

Quote from lethman427

This is caused by the launcher launching with the wrong main class

Quick Fix:
- Go to AppData/.minecraft
- Open the Version folder
- Open the affected version
- Open the .json file in a text editor
- change the following line (near bottom):
- "mainClass": "net/minecraft/client/main/Main"
to
- "mainClass": "net.minecraft.client.Minecraft"

When I do this and try runnnig Minecraft again, I receive the same message as before and it appears to change the text back when I return to look at the .json file.