Unable to read a class file correctly
java.lang.SecurityException: SHA-256 digest error for mods/railcraft/common/carts/LinkageHandler.class
	at sun.security.util.ManifestEntryVerifier.verify(ManifestEntryVerifier.java:218)
	at java.util.jar.JarVerifier.processEntry(JarVerifier.java:241)
	at java.util.jar.JarVerifier.update(JarVerifier.java:228)
	at java.util.jar.JarVerifier$VerifierStream.read(JarVerifier.java:482)
	at org.objectweb.asm.ClassReader.a(Unknown Source)
	at org.objectweb.asm.ClassReader.<init>(Unknown Source)
	at cpw.mods.fml.common.discovery.asm.ASMModParser.<init>(ASMModParser.java:52)
	at cpw.mods.fml.common.discovery.JarDiscoverer.discover(JarDiscoverer.java:72)
	at cpw.mods.fml.common.discovery.ContainerType.findMods(ContainerType.java:42)
	at cpw.mods.fml.common.discovery.ModCandidate.explore(ModCandidate.java:71)
	at cpw.mods.fml.common.discovery.ModDiscoverer.identifyMods(ModDiscoverer.java:131)
	at cpw.mods.fml.common.Loader.identifyMods(Loader.java:364)
	at cpw.mods.fml.common.Loader.loadMods(Loader.java:489)
	at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:208)
	at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:480)
	at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:878)
	at net.minecraft.client.main.Main.main(SourceFile:148)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:483)
	at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
	at net.minecraft.launchwrapper.Launch.main(Launch.java:28)