I also haven't had any automatic backups. I did a manual backup on July 27 and when I checked on Sept 1, there no backups taken since the July 27 manual backup. I did another manual backup on Sept 3 and no further backups have occurred. The manual ones are going to the location specified at Tools>Options>File Location>Program Files>Library Backups.
I have the backups going to an external hard drive. I've checked all my drives for .zip files, and the ones that are MC related are the manual backups. I didn't have this problem with prior versions of MC. Are scheduling the backups the only other option or is there something else I should investigate?