title: The content is blocked because it isn't signed by a valid security certificate error in Outlook addin
body: <p>I have developed an Outlook add-in which is required to open an authentication dialog before performing a job. I am facing two issues which I think are inter-related.</p>
  <ol>
  <li>Though the add-in works fine in Edge and Chrome, the dialog doesn't appear in IE. I don't see any error in the console also regarding this.</li>
  <li>I see below error when it tries to open the dialog.
  <a href="https://i.stack.imgur.com/REPkS.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/REPkS.png" alt="enter image description here" /></a></li>
  </ol>
  <p>I am installing the certificates using <code>npx office-addin-dev-certs install</code>, and have already re-installed them as recommended in different forums. Also, my Outlook version is up-to-date.</p>
  <p>Any help is appreciated.</p>