I had a single install, I updated the wp-config.php and .htaccess to create a subdomain based multisite. Initially I had issues with accessing the network admin. I then redid the process, it worked. Then I added a number of subdomains. The issues then started here. I couldn't access the subdomain admins or the website.
I've installed a wildcard ssl cert on *.howto*****.com that is pointing to the root folder of my multisite, not sure if I’m skipping something else.
I’m getting “Index of /“ if trying to access the front-end and an Internal Server Error if trying to access the admin.