Something crashed my theme/site

Hi! I have had a crash that I haven't been able to solve using the typical ways, such as through FTP. My business partner was playing around with some plugins

We had two different "wp experts" look at this, one said she renamed every plugin file, and both had no luck fixing. I tried disabling plugins through FTP to see if the site would start working, as normally this is the fix.

The website is http://www.serenesocial.com, and you can see the webpage is not at all showing as it should be. Also, admin login is supposed to be at http://www.serenesocial.com/wp-admin, however now the page isn't even loading.

This is general WordPress help, as I don't believe the crash happened using a WPMUDEV plugin. I appreciate all the support in helping to get this website back up! Thank you!!