Hard to tell. It could be many things. There may be an issue with your Excel installation. I have used this add-in with several cohorts of students in the past few years and have not had a problem with it making Excel crash before. I'd try re-installing Excel, if possible, or at least checking to see if there are any available software updates that you haven't yet installed.

Both add-ins can be purchased at: treeplan.com.

Not sure. I've never tried. You can try contacting the vendor through their web site and ask them directly.

@@TallysYunes Thanks!