Minecraft Forums

Basically,it was fine a few days ago. Lately,I've been getting massive lag in multiplayer. I know my ping on tab isn't accurate,but as of now it's on 2-3 bars. Normally,it always has all 5 bars.

Anyway,this happens on multiple different servers and it is not my internet connection,since it runs flawlessly with other online games. Help would be VERY MUCH appreciated.

I tried deleting all my 1.6 version folders and re-obtaining the 1.6 jar. I was greeted with the following crash message before the game even opened:
*** MagicMinecraftLauncher 1.2.5 ***
LCP: C:\Users\Joao\Downloads\OptiFine_1.6.4_HD_U_C5.jar;C:\Users\Joao\AppData\Roaming\.minecraft\versions\1.6.4\1.6.4.jar;bin/jinput.jar;bin/lwjgl.jar;bin/lwjgl_util.jar
MainClass: net.minecraft.client.Minecraft
java.lang.ClassNotFoundException: net.minecraft.client.Minecraft
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(SourceFile:181)