title: Ruby on Rails TypeError
body: <p>I have been working on a ruby on rails application and ran into the following error when doing just about anything, including installing a gem, updating the bundle, installing the bundle.</p>
  
  <p><code>ERROR:  While executing gem ... (TypeError)
      incompatible marshal file format (can't be read)
      format version 4.8 required; 31.139 given</code></p>
  
  <p>I have uninstalled RVM and completely removed all files from it, then tried to install a gem, but still get the same error.</p>