It turns out I had a plugin called Roles and Responsibilities that had changed the setting for the administrator so that role couldn’t see or change the theme even though the plugin said that it didn’t change any admin settings so I don’t know why it did. It did it without my knowledge and was only visible in the database. My ISP had to go in and change it back using settings from another WordPress site. After that, I deleted the plugin and all is back to normal.
