Subdomain Add Site Error

I have set up a multisite network on my subdomain dsnfoundation.svtpublishing.com

I cannot setup the multisite on my main domain because this is created for a client and I have other things there. Long story short, when this site goes live for him, it will be a multisite network hence why I set it up this way on the subdomain.

But now I’m running into the issue then when I create a new site such as
dsnfoundation.svtpublishing.com/dolbymusic/ – the wp-admin is blank and trying to access that address directly gets several errors.

I’ve searched everywhere but I can’t seem to find the fix for this. Please to help?