Exception in thread "main" java.lang.NoClassDefFoundError: net/minecraft/client/main/Main
[10:49:53 INFO]: Client> Caused by: java.lang.ClassNotFoundException: net.minecraft.client.main.Main
[10:49:53 INFO]: Client> at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
[10:49:53 INFO]: Client> at java.security.AccessController.doPrivileged(Native Method)
[10:49:53 INFO]: Client> at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
[10:49:53 INFO]: Client> at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
[10:49:53 INFO]: Client> at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
[10:49:53 INFO]: Client> at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
Log shows
As far as I know, based on other reports with this, this is automatically invalid.