The possible reasons and solutions behind purchase code registration keep loading during xeroChat installation are below.
1. In your server all files & folder doesn't have write permission.
2. SSL configuration issue in your server.
1. Make sure to provide write permissions to all folders & files. 755 should work , but depends on your server user group, it may needs 777 permissions.
2. If the problem comes for SSL configuration : This mostly happen for using cloudflare. If it's cloudflare try by switching SSL mode to Full stead of Flexible .
If this doesn't work, then edit file application/config/config.php line no 17
$config['base_url'] = "Application URL/ ";
Replace Application URL by actual url of the XeroChat and a trailing slash Example : https://xerochat.com/demo/ or where xerochat is installed flowing a trailing slash.
Still if you facing problem, open a support ticket providing your application url, admin login crededentil to check the actual issue.