title: Xcode 7.3 does not show up any downloadable iOS simulator
body: <p>Just upgrade my Xcode from 7.2.1 to 7.3. Have no idea why. Do I have choices other than delete Xcode and reinstall again? (which I highly don't like).</p>
  
  <p>BTW, the documentation tab is fine. Just a blank simulators.</p>
  
  <p>Update: If I click "check and isntall now", it reports:</p>
  
  <p><strong><em>Could not download and install OS X 10.11.4 Documentation. The certificate for this server is invalid. You might be connecting to a server that is pretending to be “devimages.apple.com.edgekey.net” which could put your confidential information at risk.</em></strong></p>
  
  <p>I checked cert on <a href="https://devimages.apple.com.edgekey.net" rel="nofollow noreferrer">https://devimages.apple.com.edgekey.net</a>, seems fine..</p>
  
  <p><a href="https://i.stack.imgur.com/yj9Ez.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/yj9Ez.jpg" alt="enter image description here"></a></p>