iMovie not importing still images

Hi there. I've been using iMovie for a long time, issue free. For some reason it doesn't seem to want to import jpgs or images of any sort today.

.mov files are coming in fine, but if I try to drag and drop in or import a still image I get a circle with a line through it.

I already restarted the app, restarted the Mac, and deleted the iMovie prefs.