If you go to cmd and type "java -version" you will see the java version that is configured there. In your case probably an older version of java.
Thanks! I got it to work with keeping the JDK (for some reason the JRE was overwrting the path, once I unistalled it leaving just the JDK it worked). Also Confiming like the others above, after deleting "province_mapping" my mod loads and works! Thanks Jon this is an awesome Tool and great help to modders.