title: vim cgn "E35: No previous regular expression"
body: <p>I am pretty new to vim (on macOS highsierra and vim installed via homebrew) and I was trying to mark and replace a text object with the cgn command sequence. This was working a few times, but all off a sudden on <code>cgn</code>, I keep getting this error message</p>
  
  <blockquote>
    <p>E35: No previous regular expression</p>
  </blockquote>
  
  <p>As far as I understand this error might occur when the user has no rights to write to <code>~/.viminfo</code>. So I explicitly set</p>
  
  <pre><code>sudo chmod 666 .viminfo
  </code></pre>
  
  <p>But I still keep getting this error message.</p>