Correct Manifest file name and NPE checks

Upgrading from JRE 8.0.281 to JRE 8.0.291 throws the following exceptions:
 
basic: exception: java.lang.reflect.InvocationTargetException.
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
              at sun.plugin2.applet.Plugin2ClassLoader.defineClassHelper(Unknown Source)
              at sun.plugin2.applet.Plugin2ClassLoader.access$100(Unknown Source)
              at sun.plugin2.applet.Plugin2ClassLoader$2.run(Unknown Source)
              at sun.plugin2.applet.Plugin2ClassLoader$2.run(Unknown Source)
              at java.security.AccessController.doPrivileged(Native Method)
              at sun.plugin2.applet.Plugin2ClassLoader.findClassHelper(Unknown Source)
              at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source)
              at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
              at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
              at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
              at java.lang.ClassLoader.loadClass(Unknown Source)
              at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Unknown Source)
              at sun.plugin2.applet.Plugin2Manager.initAppletAdapter(Unknown Source)
              at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
              at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.reflect.InvocationTargetException
              at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
              at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
              at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
              at java.lang.reflect.Method.invoke(Unknown Source)
              ... 15 more
Caused by: java.lang.NullPointerException
              at java.util.Hashtable.contains(Unknown Source)
              at java.util.Hashtable.containsValue(Unknown Source)
              at sun.security.util.ManifestEntryVerifier.getParams(Unknown Source)
              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$VerifierStream.read(Unknown Source)
              at sun.misc.Resource.getBytes(Unknown Source)
              at sun.plugin2.applet.Plugin2ClassLoader$WrapResource.getBytes(Unknown Source)
              at java.net.URLClassLoader.defineClass(Unknown Source)
              ... 19 more