HTTP 500 Internal Server Error for Added Sites

Hi, I’ve recently downloaded the mu-plugin for WordPress that allows users to create their own blogs, and I ran into some trouble trying to add a new site. Fortunately, I was able to add one; however, whenever I’d try to visit, edit or goto it’s dashboard, I’d be redirected to an “HTTP 500 Internal Server Error” page with a “The website cannot be displayed” notice. Any suggestions?
Many thanks for your time and consideration, any support would be much appreciated.
Faith