I see the problem but we didn’t have this issue with theme. Also there isn’t any errors in console so this makes problem even more weird.
As I can see you have latest version of theme (v1.4). Last version of Content Manager is v1.1.6 so if you don’t have last version update it from Appearance -> Install plugins.
Try also update Revolution slider if it’s not updated, you can find last version in this topic:
If nothing of this help I will take a look what is going on.