title: Office-js: Excel addin failed to load when reopening the excel file
body: <p>We noticed the add-in failed when a file is reopened. The reopen I mean:</p>
  
  <ul>
  <li>Open a new, Add add-in (which works fine)</li>
  <li>Save a file </li>
  <li>Reopen the file. Then the Add-in failed with “Add-in Warning  This add-in is not available in Office Online.”</li>
  </ul>
  
  <p>All the browsers (i.e., Excel online) and iPad Excel scenarios failed and others are ok.</p>
  
  <p>Is this an known issue?</p>