Adding Playlists to Virtual Channels

Is it no longer possible to add a playlist to a virtual channel? I had created multiple virtual channels using playlists, but I am no longer able to add or even edit playlists on virtual channels. However, existing virtual channels still seem to be poplulating the schedule with the content of the playlists. For example, this Star Wars channel is still running, but there is no content visible at the top like usual. Perhaps I am doing something wrong, as I am relatively new to Channels.

Any guidance would be appreciated. Thanks!