--- old/src/java.base/share/classes/jdk/internal/loader/ClassLoaders.java	Tue Mar  8 21:59:18 2016
+++ new/src/java.base/share/classes/jdk/internal/loader/ClassLoaders.java	Tue Mar  8 21:59:17 2016
@@ -133,7 +133,8 @@
     private static class ExtClassLoader extends BuiltinClassLoader {
         static {
             if (!ClassLoader.registerAsParallelCapable())
-                throw new InternalError();
+                throw new InternalError("Classloader is not registered" +
+                    " as parallel capable.");
         }
 
         ExtClassLoader(BootClassLoader parent) {
@@ -158,7 +159,8 @@
     private static class AppClassLoader extends BuiltinClassLoader {
         static {
             if (!ClassLoader.registerAsParallelCapable())
-                throw new InternalError();
+                throw new InternalError("Classloader is not registered" +
+                    " as parallel capable.");
         }
 
         final URLClassPath ucp;