title: What does "Fatal error: Unexpectedly found nil while unwrapping an Optional value" mean?
body: <p>My Swift program is crashing with <code>EXC_BAD_INSTRUCTION</code> and one of the following similar errors. What does this error mean, and how do I fix it?</p>
  
  <blockquote>
    <p>Fatal error: Unexpectedly found nil while unwrapping an Optional value  </p>
  </blockquote>
  
  <p><em>or</em></p>
  
  <blockquote>
    <p>Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value  </p>
  </blockquote>
  
  <hr>
  
  <p><sup>This post is intended to collect answers to "unexpectedly found nil" issues, so that they are not scattered and hard to find. Feel free to add your own answer or <a href="https://stackoverflow.com/posts/32170457/edit">edit</a> the existing wiki answer.</sup></p>