I deactivated WP All in One Security on my Multisite (approx. 170 small sites), as you suggested and ran Snaphot. This time it did produce a backup and put it in Dropbox. So I wanted to make sure it was a complete backup and checked the log file. There are still many lines that say permission denied. I can't imagine that this is the way it should be.
Is there a way to check the completeness of the backup and ensure that I am getting perfect backup files?