If you're getting an error like this: java.lang.UnsupportedClassVersionError: _dasadmin_3__UTF_s8/_index : Unsupported major.minor version 51.0 ..... ..... [PageCompileServlet] Error compiling page: /index.jhtml : can't load class: _dasadmin_3__UTF_s8._index You need to change the javac from your machine, in order to match the java version used for building the code. For Ubuntu: 1. Open the terminal and run this: sudo update-alternatives --install /usr/bin/java java /opt/java/jdk1.6.0_25 1 2. It will install the jdk, now you need to select it from the alternatives sudo update-alternatives --config java 3. And select the one corresponding to the jdk you require 4. Then you must do the same for javac sudo update-alternatives --install /usr/bin/javac javac /opt/java/jdk1.6.0_25/bin/javac 1 5. And update the config within alternatives too: sudo update-alternatives --config javac 6. And select the one corresponding to the jdk you require 7. Remember to updat