Lost ability to switch from plain text to rich text editor?

Somehow the site I'm working on lost the ability to switch from plain text to rich text editor (WSYWIG options) in the core body field. It's happening on all content types (even basic). I inspected the area below the body field and see that the link is there, but there's a display:none style on it and not sure how that happened. I'm going to try to force the visibility by applying display: block on it, but no idea how this happened. Is this happening for anyone else? Is there a Drupal configuration I need to be aware of vs. applying what I'm thinking of (which seems like a hack).