Thanks, Kevin, but I can't anymore as I changed the file in the meantime. It was in 4.6.23, the latest alpha I have. On Win 10.
I just made a sort of similar file, but couldn't replicate it either. And like I said, the later tries didn't crash either, so it was just the first 6 sessions in a row.
I'll report back if it occurs again, and save the file then.
EDIT: just installed 4.6.31 and couldn't replicate it either.