When I try to start minecraft after installing forge it gets about 95% done loading and stops.

 

Error Log:

 

===Simple Minecraft Error Test===

 

Starting Minecraft...

 

Exception in thread "main" java.lang.SecurityException: SHA1 digest error for

t/minecraft/client/Minecraft.class

        at sun.security.util.ManifestEntryVerifier.verify(Unknown Source)

        at java.util.jar.JarVerifier.processEntry(Unknown Source)

        at java.util.jar.JarVerifier.update(Unknown Source)

        at java.util.jar.JarVerifier$VerifierStream.read(Unknown Source)

        at sun.misc.Resource.getBytes(Unknown Source)

        at java.net.URLClassLoader.defineClass(Unknown Source)

        at java.net.URLClassLoader.access$100(Unknown Source)

        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)

        at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)

 

Finished session

 

 

 

 

Can anyone help?

Did you delete META_INF? If yes, try an another archiver like 7zip and do it again with a fresh jar file! Looks like your archiver screws things up.

I had forgotten to delete the META-INF folder, thank you for your help.