title: Java app (jar) working in Windows but not Linux (made in Eclispe)
body: <p>I've made this application in a Windows environment. In eclipse, I made an executable .jar file by going to <code>File &gt; Export &gt; Executable Jar</code></p>
  
  <p>I can launch the app in Windows by openening it with Java. However in Linux, when I run <code>java -jar app.jar</code>, I get this:</p>
  
  <pre><code>Exception in thread "main" java.lang.UnsupportedClassVersionError: ConfigReader (Unsupported major.minor version 50.0)
          at java.lang.ClassLoader.defineClass0(Native Method)
          at java.lang.ClassLoader.defineClass(ClassLoader.java:539)
          at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:123)
          at java.net.URLClassLoader.defineClass(URLClassLoader.java:251)
          at java.net.URLClassLoader.access$100(URLClassLoader.java:55)
          at java.net.URLClassLoader$1.run(URLClassLoader.java:194)
          at java.security.AccessController.doPrivileged(Native Method)
          at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
          at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
          at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:274)
          at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
          at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302)
  </code></pre>
  
  <p>What does unsupported class version error mean?</p>