After I switched to java 8 I've been getting this error:

Exception in thread "main" java.lang.SecurityException: Invalid signature file digest for Manifest main attributes at sun.security.util.SignatureFileVerifier.processImpl(SignatureFileVerifier.java:325) at sun.security.util.SignatureFileVerifier.process(SignatureFileVerifier.java:267) at java.util.jar.JarVerifier.processEntry(JarVerifier.java:285) at java.util.jar.JarVerifier.update(JarVerifier.java:239) at java.util.jar.JarFile.initializeVerifier(JarFile.java:402) at java.util.jar.JarFile.ensureInitialization(JarFile.java:644) at java.util.jar.JavaUtilJarAccessImpl.ensureInitialization(JavaUtilJarAccessImpl.java:69) at sun.misc.URLClassPath$JarLoader$2.getManifest(URLClassPath.java:965) at java.net.URLClassLoader.defineClass(URLClassLoader.java:456) at java.net.URLClassLoader.access$100(URLClassLoader.java:74) at java.net.URLClassLoader$1.run(URLClassLoader.java:369) at java.net.URLClassLoader$1.run(URLClassLoader.java:363) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:362) at java.lang.ClassLoader.loadClass(ClassLoader.java:418) at java.lang.ClassLoader.loadClass(ClassLoader.java:351) at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Class.java:2701) at java.lang.Class.privateGetMethodRecursive(Class.java:3048) at java.lang.Class.getMethod0(Class.java:3018) at java.lang.Class.getMethod(Class.java:1784) at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:690) at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:672)

any idea how to fix this?

tks in advance