I've been fighting with this for 2 days so hopefully someone can offer a suggestion or three.
I configured Multisite using subfolders. When I create a site the site is visible but the new site's dashboard loses all formatting and I get a blank page when I click on any of the links in the dashboard. My primary site's dashboard is still working.
I am using Network Solutions to host the site, but do not believe it is a hosting issue since the main page for the new site is working.