title: Emacs "error in process filter: menu-bar-update-yank-menu: Wrong type argument: stringp, nil"
body: <p>I maintain a elisp project at <a href="https://github.com/coordinate/bingapiel" rel="nofollow">https://github.com/coordinate/bingapiel</a>.</p>
  
  <p>It is for translating with bing api in emacs.</p>
  
  <p>Some users complain about that error :</p>
  
  <pre><code>error in process filter: menu-bar-update-yank-menu: Wrong type argument: stringp, nil
  error in process filter: Wrong type argument: stringp, nil
  </code></pre>
  
  <p>But I can not reproduce the error on my computer.</p>
  
  <p>So I'm here for help. Did anyone encountered this error too. Does anyone know the meaning of "menu-bar-update-yank-menu: Wrong type argument: stringp, nil". Any suggestion is welcome.</p>