Android 6.0 - how to update rooted and tweaked MotoG 2015
The issue here is that the installer is expecting the current build to be that of their retail ROM. Your method of rooting has been specifically marked for debug purposes (aka: rooted) and it doesn't want to continue.

Honestly if you want updates and support, either unroot your device or go to a custom ROM. As for keeping your stuff, use Titanium Backup to make a copy of all your stuff. You can restore it later if you go down the custom ROM route