 <p><strong>update may 27:</strong></p> <p>we just released an update (<code>version 9.0.1</code>) to fix the incompatibility I mentioned in my first edit.<br> Please update your dependencies and let us know if this is still an issue.</p> <p><em>Thanks!</em></p> <hr> <p><strong>original answer May 20:</strong></p> <p>The issue you are experiencing is due to an incompatibility between<br> <code>play-services / firebase sdk v9.0.0</code> and <code>com.android.support:appcompat-v7 &gt;= 24</code><br> (the version released with android-N sdk)</p> <p>You should be able to fix it by targeting an earlier version of the support library. Like:</p> <pre><code>compile 'com.android.support:appcompat-v7:23.4.0' </code></pre>