title: Whatever I do always get error : Keystore file exists but is empty In Unity
body: <p>I have browsers with so many threads and postings about "Keystore file exist But is empty", but i can't find a really suitable question and answer match with mine in Unity.</p>
  
  <p>I want to generate a release hash key for login with facebook using facebook sdk 7.9. Since the debug in editor login ran successfully. The problem is when running on the device.</p>
  
  <p>Then I have found a thread that teaches how to show all keystores with an alias.</p>
  
  <p>Below is how to do it :</p>
  
  <ol>
  <li>Open CMD</li>
  <li>Use Command : "keytool -list -keystore "PATH YOUR KEYSTORE"</li>
  <li>Enter</li>
  </ol>
  
  <p>In this "PATH YOUR KEYSTORE" change with your path ex: </p>
  
  <pre><code>c:\unity_project\TTS\mykey
  </code></pre>
  
  <p>But what I get does not always reveal the keystore and the alias. What i get is an error: </p>
  
  <pre><code>keytool error: java.lang.Exception: Keystore file exists, 
  but is empty: c:\unity_project\TTS\mykey
  </code></pre>
  
  <p>Why do I always got this error?</p>
  
  <p>I have already created a keystore and the keystore is saved in this path:</p>
  
  <pre><code> c:\unity_project\TTS\mykey
  </code></pre>
  
  <p>I have also created a key from the keystore. This can be created with the build setting: </p>
  
  <pre><code>[![enter image description here][1]][1]
  
  [1]: https://i.stack.imgur.com/Glim2.png
  </code></pre>
  
  <p>Then I have built it without check "Development Build".</p>
  
  <p>So why do I always get the above error? Is it because I need to generate a release hash key for that keystore alias key.</p>
  
  <p>Thanks</p>
  
  <p>Dennis</p>