I enabled accessibility mode, but it still does nothing. I assume this might be an issue with the theme (Nimble was installed by someone before I started maintaining the site), but I have no idea. It’s driving me crazy.
Ok, I temporarily solved. If you go back a theme it updates the cache and the widgets appear now. Annoying to have to go every time you change something, but whatev. Any suggestions as to how to stop this?
For anyone with this issue, change themes then go back to the theme you like and the widgets should show.
Looks like Nimble is from Elegant Themes? Perhaps ask on their forums — as they do provide support for purchased themes.