title: eclipse marks every new project with an exclamation mark
body: <p>My eclipse marks every new project with an exclamation mark.
  <img src="https://i.stack.imgur.com/pKmVp.jpg" alt="enter image description here"></p>
  
  <p>i tried the steps provided here: <a href="https://stackoverflow.com/questions/2083461/unbound-classpath-container-in-eclipse">Unbound classpath container in Eclipse</a> but no cigar.</p>
  
  <p>i was able to delete java 1.7 and add the old 1.6 but now i get this error:</p>
  
  <pre><code>java.lang.UnsupportedClassVersionError: klasse : Unsupported major.minor version 51.0
  at java.lang.ClassLoader.defineClass1(Native Method)
  at java.lang.ClassLoader.defineClassCond(Unknown Source)
  at java.lang.ClassLoader.defineClass(Unknown Source)
  at java.security.SecureClassLoader.defineClass(Unknown Source)
  at java.net.URLClassLoader.defineClass(Unknown Source)
  at java.net.URLClassLoader.access$000(Unknown Source)
  at java.net.URLClassLoader$1.run(Unknown Source)
  at java.security.AccessController.doPrivileged(Native Method)
  at java.net.URLClassLoader.findClass(Unknown Source)
  at java.lang.ClassLoader.loadClass(Unknown Source)
  at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
  at java.lang.ClassLoader.loadClass(Unknown Source)
  </code></pre>
  
  <p>Exception in thread "main" </p>
  
  <p>im pretty much lost. java seems simply broken to me. maybe i should just reinstall it?</p>
  
  <p>/Edit: since some dont believe me:
  <img src="https://i.stack.imgur.com/C8PSK.jpg" alt="enter image description here"></p>
  
  <p>there is no problem with klasse.java (some other projects have some normal errors that i cannot bother and CSVAufbereitung has the error i had in klasse.java before i followed the steps above. </p>
  
  <p>(thats why i created this question in the first place)</p>
  
  <p><strong>IMPORTANT</strong>: i just realized that i only have the jre1.6 installed while having jdk1.7 and jre1.7 installed.</p>
  
  <p>so when i switch back to 1.6 it wont work because i dont have jdk1.6 installed.</p>
  
  <p>silly me. but i would like to keep using 1.7</p>
  
  <p>so the main question is: why is 1.7 not useable anymore ("Unbound")?</p>
  
  <p><strong>Update:</strong> </p>
  
  <p>i found out that i can create 1.6 project and they will run without errors.</p>
  
  <p>if i create projects with 1.7 they wont run.</p>
  
  <p>if i then downgrade those projects to 1.6 they still wont run.</p>
  
  <p>since i want to use 1.7 this is quite nagging.</p>