Minecraft.jar is corrupted?

Whenever I try to run the minecraft.jar in my.minecraft folder I get the message:

"Error: Invalid or corrupt jarfile
C:\Users\COMP\AppData\Roaming\.minecraft\minecraft.jar"

As a result, I can't use any other shortcut to play the game. I've tried everything I can think of… Deleting the.minecraft folder, system restore, finding backups of all of my files on my harddrive before I had this issue, but nothing is working.

I believe this happened because in an attempt to update my java, I simply deleted the Java folder from my Program Files. But, even having replaced the files with my backups, Minecraft refuses to work. If I delete the files, it does not reinstall itself or make new files, it simply keeps giving me the same error message.

I'm working on Windows 8.1, 8gb ram, HP Envy 6.

Guest

Try redownloading Java. Also force update Mine craft. If that doesn't work than delete minecraft and Java altogether and recompile them both.

Bob

Easiest way to Re-Set your minecraft is to go into your.Minecraft and delete the file names BIN, when you start up minecraft from the shortcut (Or whatever) it will "Update" and re-Download the Bin folder.

This works because The bin folder contains the Minecraft.Jar which is the file used when modding minecraft, and solely deleting the.Jar will not prompt minecraft to "Update" and download another.

Randall T

This happened to me when i got it, First off Uninstall All versions of minecraft you have on your PC, make sure all the files are gone because left over files can corrupt the new install. Next see if your JAVA need updating -
https://www.java.com/.../download/

After java has been updated/check for an update go and download minecraft again -
https://minecraft.net/...t/download

After load your Minecraft back up and it should fix the problem!

If not go to START --> (Find java folder or file) Configure JAVA --> Where it says about RAM increase the amount it uses. This is for systems that have around 3-4GB of ram if you have less ram don't allocate any more, unless its really low make sure its got at lease 1024MB of ram allocated. You have 8GB of ram so that should be fine.

here is a guide on how to allocate more ram to minecraft -
http://www.wikihow.com/Allocate-More-RAM-to-Minecraft

If you installed any mods remove them, sometimes they can mess with your game state.

If that don't work your system may not be powerful enough to run minecraft but i highly doubt thats the problem,
Hope i helped a little!

Luke_Games