I see a blank page or "404 Not Found" after uploading
Your server needs URL rewriting. On Apache, make sure mod_rewrite is enabled and the site allows .htaccess overrides (AllowOverride All). On Nginx, add a try_files rule pointing to index.php. Your host can enable this in a minute.
The database step says the connection failed
Double-check the host (often "localhost" or "127.0.0.1"), database name, username and password from your hosting control panel. The database must already exist, and the user must have full privileges on it.
How do I run the installer again?
Delete the file storage/app/private/.install-locked on your server, then visit the site again. (This does not erase data — only re-opens the wizard.)
Where do I find my license key?
Open your CodeCanyon account, go to the Downloads section, and download the License certificate for this item. The Purchase code inside that file is your license key — paste it on the license step.