Categories Sidebar Widget NOT showing categories

I am trying to use the Categories widget for the sidebar of my blog, but it doesn’t list any of the categories and says “No Categories,” even though I have many functioning categories. Any tips on how to fix this?

I had to import the posts in an .xml file from an old WordPress.com blog so I’m not sure if that has anything to do with it. But everything else seemed to import well.

http://wadsworthmansion.1059creative.net/?page_id=21732

Thanks!