I've seen this plugin work on other installs. The documentation seems to me to be incomplete. For example, I get red errors when I verify one of my network sites. But there is no where that tells you how to find and resolve the proper setting associated with the error.
The doc is quite brief in terms of install, setup and management. Yet there seems to be a wealth of settings necessary in order top get a network site to work and to be able to assign a theme to it, etc.
Bottom-line winds up causing grief & frustration.