title: Android studio 2.12 - out-of-the-box App Widget - "Error Launching Activity"
body: <p>I was developing an android Widget, which was functional, if not finished. Android Studio proposed an upgrade, but my version was too far behind, so I had to download the whole studio, not a patch. When installing, it left me no choice but to delete the previous version while installing.</p>
  
  <p>When trying to install my widget on a device, after the installation succeeded, this message came up :</p>
  
  <pre><code>Could not identify launch activity: Default Activity not found
  Error while Launching activity
  </code></pre>
  
  <p>After googling, and failing to find a solution, I decided to create a new project (android 2.3), create a new App Widget (right-click package > new > widget > app widget), and not change a single line of code.</p>
  
  <p>I get the very same behaviour as with my own package.</p>
  
  <p>I have tried at various times to "Invalidate Cache / Restart"; currently I am investigating gradle of which I know next to nothing. In the course of this, I clicked some things (in my memory, right-click > properties, on some file), but I can't find it again, which opened a window which proposed something close to "default behaviour > launch activity / do nothing / other choices... ". This might well do the trick.</p>
  
  <p>Can someone point me to this found and lost dialog box?</p>