I’m not sure why you have several plugins active which do the same job. You have activated “Autoptimize” and “better wordpress minify”. Both these plugin’s job is to minify css/js. We recommend you to only use one plugin for one job or else it’ll only complicate the process as well as slow down the webiste. Also “W3 Total cache” plugin is active which also has Cache and Minify features.
So, first thing would be to decide which plugin you want to use. For now I’ve deactivated Better WP minify plugin and your site is working fine.