Hi Ellen Saxon I'm sorry to hear that you're running into a crash.
I looked into this and it looks like you have submitted at least one error report - thank you for submitting that.
From what I can tell, while we do see that the crash occurs in 10.7.1, I'm not seeing any reports of it in 10.8. That doesn't necessarily mean it doesn't occur in 10.8, it could be that nobody has done the same thing with the same data (you've noted it doesn't occur with all dwgs...) in 10.8. Anyway, upgrading could be worth a shot if possible.
Are you able to send the dwg that causes the crash? Along with steps to reproduce it? That way we can have the development team take a closer look to better understand what it causing the failure. Please email to kkramer@esri.com
Thank you!