title: Qt could not find the platform plugin cocoa
body: <p>I'm experimenting a little bit with Qt. I have successfully written a small app which works fine on my Windows 8.1 Laptop. Now I installed XCode and Qt and copied the project folder to my MacBook. The application compiles fine on my Mac but when I wan't to run it via Qt Creator I'm getting the following errors:</p>
  
  <pre><code>[qt.qpa.plugin] Could not find the Qt platform plugin "cocoa" in ""
  This application failed to start because no Qt platform plugin could be initialized. Reinstall application may fix this problem.
  </code></pre>
  
  <p>I have read that the tool <code>macdeployqt</code> is needed when I want to deploy the app to other PCs. But shouldn't my application run without <code>macdeployqt</code> when I execute it directly with the Qt Creator?</p>
  
  <p>I'm using MacOS X 10.14 with Qt 5.11.3. Xcode 10 and the MacOSX SDK 10.13 is installed and setted up correctly (at least it compiles with this SDK and without any error).</p>
  
  <p>Does anyone has an idea?</p>