WordPress site crashes after activate BackWPup Free plugin

I’m using WordPress 4.1.1 and version 3.1.4 of BackWPup plugin.

When I activate this plugin, then I go directly to the ‘About’ page of this plugin. When I’m trying to go to another place, ex plugins or posts or anywhere inside the admin panel, then I get this same ‘About’ page of this plugin.

This is weird, because two days ago, I installed that plugin to test it (like I did with other plugins), I tested it (it worked fine), I uninstalled it and then, when I decided to really use it, I re-installed it after a couple of days. But now it’s just doesn’t work, it crashes my site.

https://www.ads-software.com/plugins/backwpup/