title: My copy of Eclipse doesn't know what an object or a String is
body: <p>I have a copy of Eclipse Indigo on my mac. It was working fine until I imported a project I had made on a different computer. Now I get errors like "The type java.lang.Object cannot be resolved." and "String cannot be resolved to a type". </p>
  
  <p>Also, the computer I built it on had Java 7, while my slightly broken mac has Java 6, and won't update. I'm not sure, but I suspect this may be an issue.</p>
  
  <p>What happened, and how do I fix it?</p>
  
  <p><strong>UPDATE</strong></p>
  
  <p>I put what I think is the right JRE in the build path, but now when I run it, I get these errors:</p>
  
  <pre><code>Exception in thread "main" java.lang.UnsupportedClassVersionError: Game : Unsupported major.minor version 51.0
  at java.lang.ClassLoader.defineClass1(Native Method)
  at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
  at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
  at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
  at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
  at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
  at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
  at java.security.AccessController.doPrivileged(Native Method)
  at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
  at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
  at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
  at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
  </code></pre>