App not installed

As i uploaded to make my project in to apk file, the result after downloading apk is ‘App not Installed’. I don’t know what is the exact issue is.

Can you give more information?

Where does the ‘App not installed’ message appear? In VoltBuilder, the desktop or on your Android device?

I notice you have this line in your index.html:

<script src="cordova.js" defer></script>

Try removing the defer.

I once saw this when I had another app already installed with the same certificate.