title: Android Studio 3.0 - "Failed to transform file 'gson-2.2.4.jar' to match attributes {artifactType=android-classes}"
body: <p>I'm a newcomer to Android Studio development, and I'm currently following an online <a href="http://www.tutorialsface.com/2015/08/building-your-own-android-chat-messenger-app-similar-to-whatsapp-using-xmpp-smack-4-1-api-from-scratch-part-2/" rel="noreferrer">tutorial</a> to make a messenger app. </p>
  
  <p>I've followed the steps of this tutorial, and it now needs me to download the Library files for Smack API &amp; GSON, and add the <code>.jar</code> files to the <code>libs</code> folder in my project.</p>
  
  <p>With this done, I right-clicked the files in the directory and clicked <code>Add as library</code> (the tutorial says to do <code>Build Path -&gt; Add to Build Path</code>, but this doesn't seem to be an option in this version of Android Studio).</p>
  
  <p>At this point, the project directory menu sidebar looks like this:
  <a href="https://i.stack.imgur.com/K0LY2.png" rel="noreferrer"><img src="https://i.stack.imgur.com/K0LY2.png" alt="enter image description here"></a></p>
  
  <p>From here, I tried to rebuild the project but was met with the following error:</p>
  
  <p><a href="https://i.stack.imgur.com/9H7IN.png" rel="noreferrer"><img src="https://i.stack.imgur.com/9H7IN.png" alt="enter image description here"></a></p>
  
  <p>I've not been able to find a way around this error at all, and don't know enough about Android Studio to know if this is an issue with the IDE or the package itself. I've had a look around S/O but none of the posts seem to describe the same issue, or offer any solutions to similar issues that appear to work for this too.</p>
  
  <p>If anyone has run into this before, or if it is a common Android Studio problem, would you be able to advise me on how to resolve it please? Very frustrating when I just want to get on with learning how to code for Android!</p>
  
  <p>Any help massively appreciated, thanks in advance!</p>
  
  <p>Mark</p>