Minimaze 1.3.1 loses all customizations

I upgraded to Version: 1.3.1 and now all customizations which I had before are gone. The web sites looking plain with the default minimaze slider, menus are missing, text is missing. This is the second upgrade to a new version of Minimaze that has been a disaster for us. Could you please explain? The upgrade process should be seamless except for new additions, we shouldn’t have to lose all old custom work.