Thank you very much for providing all these information.
I login to your ftp account and found that the file customizer-class.php was totally blank.
So I added in the missing content.
Then I login to your website’s admin, make sure it’s Evolve+ theme that is active.
And tried out the customizer, as mention by you, by clicking on the “Customize” button
Please see screenshot. http://prntscr.com/7agkrv
There is no fatal error now. Everything loads properly.
I did not test out the settings in case I mess up your site design.
I think something went wrong with FTP when you are uploading the theme.