title: You uploaded an APK that is signed with a different certificate to your previous APKs
body: <p>I have an existing app that has been on the market for over a year and has been through many upgrades. Recently I changed the way I built my app, making it into a library so that it would be easier to make multiple variations of the app - free/paid/alternative markets etc. etc. Now I've made some graphical changes so wish to update my standard version that is on google play, but upon uploading I get the following message:</p>
  
  <pre><code> Upload failed
  
  You uploaded an APK that is signed with a different certificate to your previous APKs. You must use the same certificate. Your existing APKs are signed with the certificate(s) with fingerprint(s):
  
  [  ]
  
  and the certificate(s) used to sign the APK you uploaded have fingerprint(s):
  
  [ SHA1: E5:FC:E7:30:F4:B2:91:16:94:3B:31:6D:B0:CA:FA:D4:A1:D8:5E:12 ]
  </code></pre>
  
  <p>So it looks like my current apk has no fingerprint (whatever that is) at all. How could that be?</p>
  
  <p><strong>EDIT:</strong> I have seen similar questions on SO, but the answers either did not apply, or I didn't understand how to implement the solutions.</p>
  
  <p><strong>EDIT:</strong> I have just found a backup of my original keystore file and used that when exporting my project. But google gave exactly the same error. So to recap, I have my original keystore file, I used the same alias, the same pair of passwords... and still have the same error.</p>