Like many people, I've been struggling with Site Categories. When I turned on Pretty URL, I receive 404 Error response when opening Category pages. When I turn off Pretty URL, pagination simply refreshes the page and doesn't load the next sites.
I changed themes, enabled DEBUG, and turned off every plugin ... or so I thought I had. Then, at the last minute, I realized, I hadn't tested it against Domain Mapping. Sure enough, when I turned off Domain Mapping, the Site Categories plugin worked as expected.
I have attached images with my settings for each plugin. They look very small when in preview mode. To view the larger image, right click on it and select "Open in a new window". Click on the image to enlarged it.
Could someone please help find a fix for this conflict soon, and bring the developers in on this if needed?