Wordpress Multisite - Subdomain Not Working

I apologize in advance for this being such a basic question but on my test domain at biztechtutorials.net I'm trying to configure a Wordpress Network as per the tutorial at:

https://premium.wpmudev.org/forums/topic/how-to-build-your-own-etsy-like-site-using-marketpress

However when I got to the point on creating a new template blog - I'm able to create a subdomain site, but when I try accessing the panel I keep getting a 404 error even though I checked the htaccess and WP-Config and they seem to be correct.

Thanks in advance for any insights.

Charles