Storyboard Pro 4.2 - unable to load audion files

I’m not able to load audio files. When I right click on the Audio track on the timeline and select “Import Audio Clips” nothing happens. When I choose File>Import>Audio Files, it takes me to the Finder window to choose a file, then I choose a file, then nothing happens. I’ve tried .mp3 and .aiff formats.
I’m on a MacbookPro, running macOS Sierra, v 10.12.6
Any ideas?