Blast Tool crashing when creating 4-deep fractures

I’m using the Blast Tool available here to create pre-fractured geometry. I am now trying to create objects with higher definition fractures but the tool keeps crashing. It seems to happen quite reliably if I import any simple FBX and click the “Apply Fracture” button 4 times in a row. All the other settings are default. I have also had it crash when trying to export an object with a 3-deep fracture.

I’ve been looking for log files, or some clue about what I might be doing wrong, but have run out of things to try. Does anyone have any ideas that might help diagnose this crash?