I've recently run into an issue in Xcode where the sks editor's preview canvas just vanishes for every project on my computer. I don't think it is an issue with my sks files because this works as expected on another computer with the same files, and when it happens it happens for ALL sks files in all projects. There used to be menu items to toggle the canvas and its settings, but those are now gone for me in sks files (they show up for swift files that have previews, however).
Any idea what is going on here? How do I get the canvas back? I literally cannot get any work done on my primary computer because of this...