eclipse

Exception in thread "main" java.lang.NoClassDefFoundError: com/mojang/authlib/exceptions/AuthenticationException
	at java.lang.Class.getDeclaredMethods0(Native Method)
	at java.lang.Class.privateGetDeclaredMethods(Unknown Source)
	at java.lang.Class.privateGetMethodRecursive(Unknown Source)
	at java.lang.Class.getMethod0(Unknown Source)
	at java.lang.Class.getMethod(Unknown Source)
	at sun.launcher.LauncherHelper.validateMainClass(Unknown Source)
	at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)
Caused by: java.lang.ClassNotFoundException: com.mojang.authlib.exceptions.AuthenticationException
	at java.net.URLClassLoader$1.run(Unknown Source)
	at java.net.URLClassLoader$1.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	... 7 more
Java HotSpot(TM) 64-Bit Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release