WordPress 4.7.3 – Theme does not work

Hi,

I got automatically updated to WordPress 4.7.3. Now the problem is that my page looks bad. The images aren’t shown and the different Homepage sections are just below each other. The CSS of the theme just doesn’t work. The menu looks like a usual unordered list (below each other and with dots in the front). The weird thing is that when I’m logged into my Dashboard it still looks the same as before.

But if clients of mine go on the website it doesn’t work. I have no idea what to do to fix this. Can you help? That’s the page: https://goo.gl/3mgJO9.

Thank you very much in advance.