Xcode 8 UIButtons with constraints not showing up
<p>Everything used to work great until yesterday I updated Xcode to version 8.</p>

<p>If I don't use any constraints, I can see the buttons but when I apply constraint(s) to the buttons they disappear, no matter what or how many constraints (height, vertical spacing, trailing etc...) I apply.</p>

<p>When I tap buttons, they act normal (events are always sent so I assume they are actually located there(?)). I tried changing text color, background color, (even adding a new UIButton) but ended with no luck. I can't see the buttons. When I change the background color of <code>Centered View</code> I can see this change on the app. The weirdest part is when I click <code>Debug View Hierarchy</code> on Xcode to see what is going on, everything looks fine there; I can see all buttons located as I expect.</p>

<p><a href="https://i.stack.imgur.com/hX2LKl.png"><img src="https://i.stack.imgur.com/hX2LKl.png" alt="Constraints"></a>
<a href="https://i.stack.imgur.com/gbLTSm.png"><img src="https://i.stack.imgur.com/gbLTSm.png" alt="Design"></a></p>

<p>Testing the app both on iPhone 5 (iOS 9.3.5) and iPhone 6 (iOS 10).</p>

<p>I am using Swift 2.3, iOS 10 and Xcode 8.</p>

<p>Is this a bug on Xcode 8? How to resolve this issue?</p>

<p><strong>UPDATE:</strong></p>

<p>I just realised same constraint problem occurs on UILabel and UIImageView too. They look fine without constraint but when I add any constraint they disappear.</p>