title: Lint found a fatal error while assembling a release target
body: <p>I was compiling my app for release and I have received an error saying this:
      Lint found fatal errors while assembling a release target.</p>
  
  <p>
  </p>
  
  <pre><code>&lt;issue
      id="UnknownId"
      severity="Fatal"
      message="The id &amp;quot;`_dynamic`&amp;quot; is not defined anywhere."
      category="Correctness"
      priority="8"
      summary="Reference to an unknown id"
      explanation="The `@+id/` syntax refers to an existing id, or creates a new one if it has not already been defined elsewhere. However, this means that if you have a typo in your reference, or if the referred view no longer exists, you do not get a warning since the id will be created on demand. This check catches errors where you have renamed an id without updating all of the references to it."
      errorLine1="        app:layout_constraintBottom_toTopOf=&amp;quot;@+id/_dynamic&amp;quot;"
      errorLine2="        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~"&gt;
      &lt;location
          file="C:\Users\Jackson\Desktop\SafetyNet\app\src\main\res\layout\activity_mock.xml"
          line="35"
          column="9"/&gt;
  &lt;/issue&gt;
  </code></pre>
  
  <p></p>