It's great that you're offering this software free of charge, but if it fails to do the one thing it's made for, there's a real problem

I'm trying to make a backup of my C: drive to an external hard-drive, connected with USB3.0.
The C drive does have over million files though, mostly images, totaling 370GB. But, this should not cause any problem.
The software gets stuck at "Prepare files lists" phase. I waited 48 hours and tried 4 times.
Here's a screenshot: http://i.imgur.com/WLJXXWG.png
I want to help this tool improve and will test any suggestions you guys have, because I think this backups software is the most straightforward and easy to use. And I think this is probably just a small problem.
Frank