title: Add-in Error: something went wrong and we couldn't start this add-in
body: <p>I'm following this <a href="http://dev.office.com/docs/add-ins/testing/debug-add-ins-in-office-online" rel="nofollow noreferrer">link</a> to run an Excel add-in.</p>
  
  <p>I have followed this <a href="https://www.youtube.com/watch?v=78wFR5Rp_Mw" rel="nofollow noreferrer">video</a> and configured localhost such that <a href="http://paste.ubuntu.com/16390558/" rel="nofollow noreferrer">Home-simple.html</a> works well in a browser:</p>
  
  <p><a href="https://i.stack.imgur.com/vr7MZ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vr7MZ.png" alt="enter image description here"></a></p>
  
  <p>I have written <code>SheetSwitcherManifest-online-3.xml</code>:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;OfficeApp xmlns="http://schemas.microsoft.com/office/appforoffice/1.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="TaskPaneApp"&gt;
    &lt;Id&gt;9475b9bb-ff88-476f-917d-33a9c632508a&lt;/Id&gt;
    &lt;Version&gt;1.0.0.0&lt;/Version&gt;
    &lt;ProviderName&gt;Microsoft&lt;/ProviderName&gt;
    &lt;DefaultLocale&gt;en-US&lt;/DefaultLocale&gt;
    &lt;DisplayName DefaultValue="Sheet Switcher - 3" /&gt;
    &lt;Description DefaultValue="Sheet Switcher - 3" /&gt;
    &lt;Capabilities&gt;
      &lt;Capability Name="Workbook" /&gt;
    &lt;/Capabilities&gt;
    &lt;DefaultSettings&gt;
    &lt;SourceLocation DefaultValue="http://localhost/Downloads/Excel-Add-in-JS-SheetSwitcher-master/TextEditor/Home-simple.html" /&gt;
    &lt;/DefaultSettings&gt;
    &lt;Permissions&gt;ReadWriteDocument&lt;/Permissions&gt;
  &lt;/OfficeApp&gt;
  </code></pre>
  
  <p>However, uploading this add-in in Excel online gives an error:</p>
  
  <p><a href="https://i.stack.imgur.com/ecUZW.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ecUZW.png" alt="enter image description here"></a></p>
  
  <p>Could anyone help?</p>