title: Eclipse won't compile, bad class file, wrong version
body: <p>I am trying to compile code checked out of SVN from another developer.  Eclipse has been giving me a lot of trouble lately.</p>
  
  <p>Here are my project-specific settings:
  <img src="https://i.stack.imgur.com/Xogi8.jpg" alt="alt text"></p>
  
  <p>This is what the compile section of my ant file:</p>
  
  <pre><code>&lt;target name="compile" depends="build-common, init" description="Compile files. "&gt;
      &lt;javac srcdir="${src_dir}" destdir="${build_dir}" debug="true" &gt;
          &lt;classpath path="${tomcat_home}/lib/servlet-api.jar;" /&gt;
      &lt;/javac&gt;
  &lt;/target&gt;
  </code></pre>
  
  <p>When I compile ( using Ant ) I get an error message:</p>
  
  <pre><code>compile:
      [javac] Compiling 3 source files to H:\MYCOMPANY\portlets\build
      [javac] H:\MYCOMPANY\portlets\src\com\mycompany\portlets\CourseList.java:3: cannot access java.io.IOException
      [javac] bad class file: C:\Program Files\Java\jre1.6.0_07\lib\rt.jar(java/io/IOException.class)
      [javac] class file has wrong version 49.0, should be 48.0
      [javac] Please remove or make sure it appears in the correct subdirectory of the classpath.
      [javac] import java.io.IOException;
      [javac]                ^
      [javac] 1 error
  </code></pre>
  
  <p>What does this error mean? </p>